Solutions for 24 bugs in Linux Mint 19


Back to the home page


No operating system is flawless. Linux Mint is no exception.

Here you'll find solutions for some bugs in Linux Mint 19 (or in the applications that are part of a default installation of Linux Mint).

Contents

  1. 1 Can't boot from install DVD: processor without PAE support
  2. 2 Computer won't boot after installation of Mint
  3. 3 Computer boots straight into Windows 8.x or 10, after dual boot install
  4. 4 The installation of Mint can't be finished: it fails halfway
  5. 5 Swap use (swappiness) is too high: Mint is too slow and uses the hard disk too much
  6. 6 Black screen after installation of the closed non-free Nvidia driver
  7. 7 The screen resolution is not right, after installation of the closed non-free Nvidia driver
  8. 8 The tools for updating or installing software malfunction
  9. 9 Reboot fails
  10. 10 Hibernate and suspend don't always work well: they make some computers malfunction or even enter a coma
    1. 10.1 Disable suspend (suspend-to-ram)
      1. 10.1.1 How to undo
  11. 11 Workaround for a FIDO U2F Security Key
  12. 12 The closed non-free Nvidia driver won't load
  13. 13 Some laptops: hard disk constantly clicks and spins up and down
  14. 14 Wireless internet is sometimes being blocked by Bluetooth
  15. 15 Large PDF documents can't be printed entirely
  16. 16 Adobe Flash Player: wrong colours (blue, pink or purple) or browser crash
  17. 17 Can't install Adobe Flash Player
  18. 18 The size of the log files in /var/log gets out of hand
  19. 19 Booting takes a very long time
  20. 20 A few graphics cards: disable hardware acceleration in your web browser
  21. 21 Repair an Xfce desktop that suddenly looks weird
  22. 22 Make your login window (LightDM) show a nice background instead of eternal night
  23. 23 Update Manager couldn't download all repository indexes
  24. 24 Computer clock time shifts between Windows and Linux Mint
    1. 24.1 How to undo local time (back to UTC)
  25. 25 Official bug lists for Linux Mint and Ubuntu
  26. 26 Want more tips?

Can't boot from install DVD: processor without PAE support

1. Does your computer have an old processor without PAE support? For many non-PAE processors from the Intel Pentium M series and Intel Celeron M series, PAE support can be forced. Which makes them fit for Linux Mint 19 after all.

You can force PAE upon such a processor by selecting Start with PAE forced in the boot menu from the Mint DVD. You can make that boot menu visible by interrupting the automatic boot, by hitting the space bar during the countdown.

Computer won't boot after installation of Mint

2. Some computers, after a seemingly flawless installation of Mint, won't boot. I'll describe two situations here.


a. You see the following error, in white letters on a black screen:

error: unknown filesystem
grub rescue>

In that case you've probably used an USB memory stick for the installation (Live USB). It happens sometimes, that the memory stick identifies itself as sda and the hard disk as sdb. And that's how it configures bootloader Grub then, during the installation!

After the installation bootloader Grub wants to boot from sdb, but sdb has disappeared: the hard disk should be addressed as sda now. The installer has therefore correctly installed and configured everything for sda, except for.... Grub.

In that case it suffices to redirect Grub to sda, which you can do as follows. The easiest method is when you use a Mint DVD for that, because then you can be sure that there will be no new switching of sda into sdb in the live session.

When you don't have the option to use a DVD, then you might try a Live USB of Xubuntu 18.04 LTS, because that one probably has no switching problem (at least in my limited experience).


b. In another situation you may see one of these two errors, in white letters on a black screen:

error: invalid arch independent ELF magic.
grub rescue>

Or this error:

error: file '/boot/grub/i386-pc/normal.mod' not found.
grub rescue>


In that case the cause may be, that Mint has installed a wrong kind of boot loader. Namely Grub for EFI / UEFI (grub-efi) instead of the ordinary Grub for BIOS.

Among others, this happens on a Lenovo B570e laptop. Although this computer has a UEFI and not a BIOS, this UEFI has been configured by Lenovo to behave as if it were a BIOS. That's why it needs the ordinary Grub for BIOS.

Reparation is then pretty simple: install the ordinary Grub with the Mint DVD.

Computer boots straight into Windows 8.x or 10, after dual boot install

3. In certain cases, after an apparently successful installation of Mint next to an existing Windows 8.x or 10, your computer might boot straight into Windows 8.x or 10. No boot menu then, in which to select Mint.

This might be caused by a wrong boot priority order in the UEFI. If so, you can fix it like this (item 2.2, left column).

The installation of Mint can't be finished: it fails halfway

4. Especially on older computers it could happen that the installation of Mint  suddenly fails. This might be caused by the slideshow.

During the installation of Mint you see a slideshow, with beautiful pictures about what to expect in your new Mint. But sometimes this slideshow creates problems: the graphics card can't handle it, because the right driver hasn't been installed yet, and the installation stalls.

In that case you can remove the slideshow like this:

Launch a terminal.
(You can launch a terminal like this: *Click*)

Use copy/paste to transfer the following command line to the terminal:

sudo apt-get remove ubiquity-slideshow-*

Press Enter.

After the removal of the slideshow you can launch the installer again.

Swap use (swappiness) is too high: Mint is too slow and uses the hard disk too much

5. This is especially noticeable on computers with relatively low RAM memory (2 GB or less): they tend to be far too slow in Linux Mint, and Mint accesses the hard disk too much. Luckily, this can be helped.

Note: does your computer have 4 GB RAM or more? Then you can skip this item, because with so much RAM you probably won't notice any benefits from applying it.

On the hard disk there's a separate partition for virtual memory, called the swap. When Mint uses the swap too much, the computer slows down a lot.

Mint's inclination to use the swap, is determined by a setting. The lower the setting, the longer it takes before Mint starts using the swap. On a scale of 0-100, the default setting is 60. Which is much too high for normal desktop use, and only fit for servers.

A detailed explanation can be found here (link dead? Then download this pdf file with the same content).

Now the how-to:

a. Check your current swappiness setting:

Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Type (use copy/paste):

cat /proc/sys/vm/swappiness

Press Enter.

The result will probably be 60.

b. Then type in the terminal (use copy/paste):

xed admin:///etc/sysctl.conf

Press Enter.

Scroll to the bottom of the text file and add your swappiness parameter to override the default, so copy/paste the following two green lines:

# Decrease swap usage to a more reasonable level
vm.swappiness=10

c. Save the text file and reboot your computer.

d. After the reboot, check the new swappiness setting:

Launch a terminal and type (use copy/paste):

cat /proc/sys/vm/swappiness

Press Enter.

Now it should be 10.

Note: if your hard disk is an SSD, your machine will benefit from an even bigger decrease in swappiness. That's because too many write actions, like frequent swapping, reduce the lifespan of an SSD. For an SSD I advise a swappiness of 1. Also check these tips for optimizing an SSD for your Linux.

Black screen after installation of the closed non-free Nvidia driver

6. When your computer boots into a black screen after you've installed the closed proprietary Nvidia driver for your video card, this is often a solution.

The screen resolution is not right, after installation of the closed non-free Nvidia driver

7. Note: the following applies only to Nvidia graphics cards running on the Nvidia restricted driver.

a. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Type (or copy/paste):

sudo apt-get install nvidia-settings

Press Enter and submit your password. Please note that the password will remain invisible, not even asterisks will show, which is normal.

b. Then type in the terminal (use copy/paste):

nvidia-settings

Press Enter.

Now you can configure your screens properly, with this handy tool from Nvidia. As follows:

- Click on "X Server Display Configuration" (in the upper left)

- On the right: click on the tab Display (probably open already)

- Resolution:click on the arrow after "Auto"

- Choose the screen resolution that you want

- Click on "Save to X Configuration File"

- Click on "Save and exit"

- Do a full reboot of your computer. Now the screen resolution should be right.

The tools for updating or installing software malfunction

8. It can happen that the tools for updating or installing software (Update Manager, Software Manager or Synaptic Package Manager) malfunction, although you do have internet connection. The cause is usually a problem with the software lists.

In that case, you often see an error report with (among other things) this text:
E: encountered a section with no package: header
E: problem with Mergelist/var/lib/apt/lists


You can solve this very easily: from the menu, launch Software Sources. Then click on the button Maintenance and then on the button Fix MergeList problems.

Ubuntu: in Ubuntu you have to do this:

a. First remove the old lists:

Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Type (use copy/paste):

sudo rm /var/lib/apt/lists/* -vf

Press Enter. Type your password when prompted; this remains entirely invisible, not even dots will show, this is normal. Press Enter again.

b. Now retrieve the new lists from the internet:

In the terminal (use copy/paste):

sudo apt-get update

Press Enter.

The problem should be over now.

Reboot fails

9. Some laptops won't reboot. The computer simply "hangs" after a rebooting attempt.

In most cases this has to do with BIOS and (U)EFI. You can remedy it as follows:

a. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

b. Then type in the terminal (use copy/paste):

xed admin:///etc/default/grub

Find the line:
GRUB_CMDLINE_LINUX=""

...and replace it by this line:
GRUB_CMDLINE_LINUX="reboot=efi"

Save the changes and close the file.

c. Now issue this command in the terminal (use copy/paste):

sudo update-grub

Press Enter. Type your password when prompted; your password will remain entirely invisible, not even dots will show, this is normal.

Now shut your computer down (no reboot!). Turn it on again, and after logging into your user account, try to reboot it. This should work now.

Hibernate and suspend don't always work well: they make some computers malfunction or even enter a coma

10. "Hibernate" and "suspend" still cause problems on some hardware, and unfortunately.... for much hardware there is no solution yet, because most manufacturers of BIOS and UEFI don't stick to the standards for implementing power saving.

Therefore it's better to turn off one or both of these sleep modes, if they don't work well on your computer.

"Hibernate" (suspend-to-disk) is the most agressive of the two sleep modes, which is why it causes problems more often than "suspend" (suspend-to-ram). If "suspend" does work well on your machine, you don't have to disable it, of course.

Both in Linux Mint and Ubuntu, "hibernate" is therefore disabled by default, but "suspend" is enabled by default. Which I think is a reasonable compromise.

Disable suspend (suspend-to-ram)

10.1. You can disable suspend (suspend-to-ram) as follows (only do it when really necessary, because it's generally a useful feature):

a. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

b. Copy/paste the following line into the terminal (make sure to use copy/paste in order to prevent typo's, it's one line!):

sudo touch /etc/polkit-1/localauthority/90-mandatory.d/disable-suspend.pkla

Press Enter.

c. Copy/paste the following line into the terminal (use copy/paste to prevent typo's, it's one line!):

xed admin:///etc/polkit-1/localauthority/90-mandatory.d/disable-suspend.pkla

Press Enter.

d. Copy and paste the following green text into that empty text file:
[Disable suspend (upower)]
Identity=unix-user:*
Action=org.freedesktop.upower.suspend
ResultActive=no
ResultInactive=no
ResultAny=no

[Disable suspend (logind)]
Identity=unix-user:*
Action=org.freedesktop.login1.suspend
ResultActive=no

[Disable suspend for all sessions (logind)]
Identity=unix-user:*
Action=org.freedesktop.login1.suspend-multiple-sessions
ResultActive=no
Save the text file and close the text editor.

e. Reboot your computer (full reboot). Suspend should now no longer be one of the options in the shutdown menu.

f. On a laptop, it's advisable to check the power manager settings: you'll have to find alternatives for suspend, for actions like closing the laptop lid.

How to undo

10.1.1. Do you want suspend back? The above hack is easily reversible. Undoing it is very simple:

Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Copy/paste the following line into the terminal (it's one line):

sudo rm -v /etc/polkit-1/localauthority/90-mandatory.d/disable-suspend.pkla

Press Enter and submit your password. Please note that the password will remain invisible, not even asterisks will show, which is normal.

Reboot your computer. The suspend option should be back now.

Workaround for a FIDO U2F Security Key

11. There are several manufacturers that produce a USB key for two-factor authentication, like for example Yubico with its Yubikey. Such a key is handy and secure.

Because of a usability regression, you probably have to configure Ubuntu and Linux Mint for the use of a FIDO U2F Security Key. Like this:

a. Install the latest Google Chrome or Chromium, because those web browsers are currently the best for using such a key. The Chrome installation package for Ubuntu and Mint is a .deb file, so you can simply double-click it in order to install Chrome.

b. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

c. Copy/paste the following line into the terminal (make sure to use copy/paste in order to prevent typo's!):

sudo apt-get install libu2f-udev

Press Enter and submit your password. Please note that your password will remain invisible, not even asterisks will show when you type it, which is normal.

d. Reboot.

e. Launch Google Chrome or Chromium and install the key, for example for your Gmail account.

f. No avail? Then try a manual approach, starting with this terminal command:

sudo touch /etc/udev/rules.d/70-u2f-generic.rules

Press Enter and submit your password. Please note that your password will remain invisible, not even asterisks will show when you type it, which is normal.

g. Now open that text file for editing, with this command line (use copy/paste to transfer it into the terminal):

xed admin:///etc/udev/rules.d/70-u2f-generic.rules

Press Enter.

h. Empty all existing contents (if any) and copy/paste the following blue text into it (don't type it!):

ACTION!="add|change", GOTO="u2f_end"

KERNEL=="hidraw*", SUBSYSTEM=="hidraw", ATTRS{idVendor}=="*", ATTRS{idProduct}=="*", TAG+="uaccess"

LABEL="u2f_end"

i. Save the modified file and close it.

j. Reboot your computer.

k. Launch Google Chrome or Chromium and install the key, for example for your Gmail account.

The closed non-free Nvidia driver won't load

12. In certain rare cases, the closed proprietary graphics driver from Nvidia won't load, although you've installed it by means of Driver Manager (and rebooted afterwards). The old open-source Nouveau driver is still in use then....

In such a case, the window of Driver Manager looks approximately like this (click on the image to enlarge it):

https://sites.google.com/site/easylinuxtipsproject/bugs/Screenshot_nvidia-driver-error.png

When that happens, this might help:

a. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

b. Copy/paste the following line into your terminal:

xed admin:///etc/modprobe.d/blacklist.conf

Press Enter.

c. In that text file, add the following three blue lines at the bottom of the existing text (use copy/paste):

# Make sure that the installed non-free Nvidia driver is being used,
# instead of the default open-source Nouveau driver.
blacklist nouveau


Save the modified file and close it.

d. Copy/paste the following command into the terminal:

sudo update-initramfs -u

Press Enter. Your password will remain entirely invisible when you type it, not even dots will show, this is normal. Press Enter again.

e. Reboot. The Nvidia driver should now be in use, which you can check with the following terminal command:

inxi -G

(continued in the column on the right)

This website is being sponsored by Google Ads.

Are you using an ad blocker? Then you're also blocking my earnings from advertisements....

If you wish to support my website, you can configure your ad blocker to make an exception for this website. Or you can make a donation (and get free goodies).

Thanks in advance....


Some laptops: hard disk constantly clicks and spins up and down

13. Some laptop hard disks have a serious problem: they keep constantly clicking and spinning up and down. Not all laptop hard disks have this problem: it depends on the brand and model.

The cause is the firmware of the disk: its power management feature has been implemented far too agressively by the manufacturer. This is very unhealthy for the disk and may shorten its lifespan considerably.

Some operating systems contain a built-in correction for this firmware error, but many types of Linux don't.

The solution is not too difficult:

Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Type (use copy/paste):

sudo hdparm -B 254 /dev/sda

Press Enter. Type your password when prompted; this remains entirely invisible, not even dots will show, this is normal. Press Enter again.

Now the nasty clicks should stop.

With this command you don't entirely disable the power management of the disk, but you limit it to a minimum. Positive side effect: your laptop becomes a little faster.

The "price" you pay is a somewhat higher power consumption, and therefore a slightly decreased battery time. But not much.

The command is for the current session only. If you want to make it permanent, you can do this:

a. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

b. Then type in the terminal (use copy/paste):

xed admin:///etc/hdparm.conf

Press Enter.

Now text editor Xed opens a text file. Add the following text, at the very end of the text (use copy paste to avoid errors):
/dev/sda {
    apm = 254
    apm_battery = 254
}
c. Save the file, close Xed and reboot your computer (full reboot).

d. Finally, disable hibernate and suspend, because the hard disk will start clicking again after waking up from those (see item 10 on this page).

This is actually no fault of Mint, but of the hard disk manufacturer, who provides bad firmware.... It's not good when an operating system has to correct a firmware fault.

Wireless internet is sometimes being blocked by Bluetooth

14. On some laptops, wireless internet (wifi or 3G) is being blocked by Bluetooth. In that case, the solution is simple: temporarily disable Bluetooth, by clicking on the bluetooth icon in the upper panel. Then reboot your laptop. Bluetooth should remain disabled and you should be able to make wifi or 3G connection.

If Bluetooth should be enabled again after reboot, disable it more thouroughly by disabling it in the BIOS of your laptop.

Large PDF documents can't be printed entirely

15. The default PDF reader in Mint sometimes has difficulty handling large PDF documents, which may cause printing failure.

To work around this problem, you can use a lightweight alternative PDF reader called xpdf. Unlike its bigger brother, xpdf has no difficulty printing large PDF documents.

You can install xpdf with a few mouseclicks in the application Software Manager, because it's present in the default software repositories of Mint.

Adobe Flash Player: wrong colours (blue, pink or purple) or browser crash

16. Not a fault of Mint, but rather annoying: on some computers, when you view video's in Adobe Flash Player, the video colors are wrong: it's all blue, purple or pink. Also Firefox may crash when viewing Flash content.

The cause is the hardware acceleration in Adobe Flash Player for Linux: this malfunctions on certain video cards.

Thankfully, there's a simple workaround that's effective: disable the hardware acceleration in Adobe Flash Player.

Note: for this workaround it's best to temporarily disable the visual effects.

- surf to the website Flash Player Help (or to another website with a certain kind of Flash content; not Youtube, because it has a different kind)

- wait until the content of the website has been loaded

- right-click mouse on the tree animation - Settings... - remove the tick for:
Enable hardware acceleration

See the screenshot below (click on it to enlarge it):

https://sites.google.com/site/easylinuxtipsproject/bugs/Screenshot-FP1.png?attredirects=0

Click the "Close" button.

Can't install Adobe Flash Player

17. Installing Adobe Flash Player is usually easy: how-to for Linux Mint (item 1.3.2, left column). But on some old computers this doesn't work, because the CPU doesn't support sse2. That support is required for the latest versions of Flash Player for Linux.

This is how you can check whether your CPU supports sse2:

Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Type (use copy/paste):

cat /proc/cpuinfo | grep sse2

Press Enter.

In the output you should find sse2 in red text. If you don't get any output at all, then unfortunately you can't use Flash Player on that machine.

A partial workaround is, to let Youtube show its content by means of html5 instead of flash: http://www.youtube.com/html5

Note: some how-to's advise in such a case, to install an older version of Flash Player, that doesn't require sse2 support. Don't do that!

Adobe Flash Player is one of the most heavily attacked applications around. Much malicious software on websites, targets Flash Player. So it's absolutely unsafe to use such an older version, also in Linux.

The size of the log files in /var/log gets out of hand

18. Thankfully it's a rare problem, but anyway: some errors create huge log files in the folder /var/log, causing rapid loss of disk space. When you have this problem, you should of course fix the underlying error(s) as soon as possible.

In order to read the gigantic log files you'd better not use a normal text editor, because it'll probably be bogged down by the sheer size of the file. Use a terminal command instead, and only for the latest entries. Like this:

An example is easiest. For examining the log file /var/log/syslog, you do this:

Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Copy/paste this command into the terminal:

tail -100 /var/log/syslog > disk_eater.log

(of course you should replace syslog by the name of the actual log file that you want to examine)

Press Enter. That way you've created a small text file, called disk_eater.log, which contains the last 100 lines in the log file. It's in your personal folder. You can simply double-cick it to read its contents. This should enable you to find the culprit.

As emergency measure you can also limit the size of the log files, which you can do as follows:

a. First make a backup copy of your current log settings, in the following way:

Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Type (use copy/paste):

sudo cp -v /etc/logrotate.d/rsyslog /rsyslogbackup

Press Enter and submit your password. Please note that the password will remain invisible, not even asterisks will show, which is normal.

c. Then type in the terminal (use copy/paste):

xed admin:///etc/logrotate.d/rsyslog

press Enter.

d. Delete the entire content of that text file and replace it by the green text below (use copy/paste):
/var/log/syslog
{
      rotate 1
      maxsize 10M
      daily
      missingok
      notifempty
      delaycompress
      compress
      postrotate
           reload rsyslog >/dev/null 2>&1 || true
      endscript
}

/var/log/mail.info
/var/log/mail.warn
/var/log/mail.err
/var/log/mail.log
/var/log/daemon.log
/var/log/kern.log
/var/log/auth.log
/var/log/user.log
/var/log/lpr.log
/var/log/cron.log
/var/log/debug
/var/log/messages
{
      rotate 1
      maxsize 10M
      daily
      missingok
      notifempty
      compress
      delaycompress
      sharedscripts
      postrotate
           reload rsyslog >/dev/null 2>&1 || true
      endscript
}
e. Save the modified text file and close it. This limits the size of each log to 10 megabytes, and the number of old copies to 1. Logrotate will be executed every day.

f. Reboot your computer.

g. Execute the following cleaning commands in the terminal. First this one:

sudo rm -v /var/log/*.gz

And then this one:

sudo logrotate -fv /etc/logrotate.conf

Note that this command line job might take a very long time. It may even seem as if the terminal has got stuck, but it hasn't: simply wait until it has finished its job, even if it would take half an hour to do it.

Then this command:

sudo rm -v /var/log/*.old

Then this one:

sudo rm -v /var/log/*.1

Finally, repeat the first command:

sudo rm -v /var/log/*.gz

h. Check the available disk space again.

Has the underlying problem been solved? Then simply delete /etc/logrotate.d/rsyslog, rename /rsyslogbackup to /rsyslog and move it to the folder /etc/logrotate.d.

Booting takes a very long time

19. On some hardware, booting lasts extremely long. You can try to find the cause of a slow boot as follows:

Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Copy/paste the following line into the terminal, to avoid errors:

systemd-analyze blame

Press Enter.

Sometimes the Network Time Protocol (NTP) is the culprit. If it's ntp.service that's eating all that time, you might try this:

Type (copy/paste to avoid errors):

sudo systemctl disable ntp

Press Enter. Type your password when required; this remains entirely invisible, not even dots will show, this is normal.

The price you pay for disabling NTP, by the way, is that your system time is no longer being synchronized with NTP servers. This is usually only a minor inconvenience.

Do you want to undo this? That's easy:

sudo systemctl enable ntp

A few graphics cards: disable hardware acceleration in your web browser

20. A video cards have trouble because of the hardware acceleration that's on by default in Firefox, Chrome and Chromium. When you experience graphics problems in those web browsers (delay when typing text, problems with displaying video's), disable it as follows:

Firefox:
Click on the button with three horizontal dashes in the top right corner - Preferences - Performance:
remove the tick for: Use recommended performance settings
then remove the tick for: Use hardware acceleration when available.
Close Firefox and launch it again.

Chrome / Chromium:
Click on the button with three dots in the top right corner - Settings - Advanced 
section System: remove the tick for: Use hardware acceleration when available.
Close Chrome / Chromium and launch it again.

Repair an Xfce desktop that suddenly looks weird

21. In case of an Xfce desktop (Linux Mint Xfce) that has suddenly started to look weird, you can try three things.

a. First the action with the least impact, namely a restart of the window manager.

- Launch a terminal window.
(You can launch a terminal window like this: *Click*)

- Copy/paste the following line into the terminal, to avoid errors:

xfwm4 --replace

Press Enter.

b. Disable all visual effects. In Linux Mint, even lightweight champion Xfce has some relatively heavy visual effects by default. Disable them like this:

Menu button - Settings - Desktop Settings
Window Manager: set it to plain Xfwm4 (instead of Xfwm4 + Compositing)

Then remove Compiz:

Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Type (use copy/paste to prevent errors):

sudo apt-get remove compiz-core

Press Enter. When prompted, type your password. Your password will remain entirely invisible, not even dots will show, this is normal.
Press Enter again.

c. If all that doesn't help, reset your Xfce desktop to its default settings as follows:

- Copy/paste the following line into the terminal:

rm -r -v ~/.config/xfce4

Press Enter.

- For the new settings to take effect, log out and log in again.

Make your login window (LightDM) show a nice background instead of eternal night

22. In Linux Mint 19, the feature of LightDM which enables you to set a nice background for it, may have a bug. Which in some cases causes the login window to have an ugly black background. This is how to work around that:

a. From the menu, launch the application Login Window.

b. Disable Draw user backgrounds (set the slider to off).

Then, in Background, select a static system background from /usr/share/backgrounds. I recommend to look for one in the folder /usr/share/backgrounds/linuxmint-tara, because that contains many beautiful images.

c. Close Login Window and reboot your computer. Now the login window should present you with a nice background.

Update Manager couldn't download all repository indexes

23. Occasionally, you might get this warning from Update Manager:
Could not download all repository indexes

With this further explanation:
An error occurred during the signature verification. The repository is not updated and the previous index files will be used.
Plus some complaining about a missing public key (NO_PUBKEY).

This might happen occasionally, when a repository maintainer changes the verification key of the repository. This means that you should load a new verification key into your system, otherwise you won't get updates for the packages that you've installed from that repo.

Google has been known to create such "key havoc" for the repository for its web browser Google Chrome. If it's Google that's plaguing you like this for Chrome, you can solve it by downloading a new key like this:

a. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

b. Use copy/paste to transfer the following command line into the terminal (it's one line!):

wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add -

Press Enter. When prompted, type your password. Your password will remain entirely invisible, not even dots will show, this is normal. Press Enter again.

That should fix it. At least until the next key change....

Computer clock time shifts between Windows and Linux Mint

24. Windows stores the time on the hardware clock as local time. Linux Mint on the other hand, stores it as UTC (formerly: Greenwich Mean Time). This causes annoying clock problems on dual boot machines.

It's easiest to make Linux Mint behave like Windows does, because Windows is more difficult to tame. It's actually a pity, because UTC makes more sense. Especially if you move your machine between time zones.

Anyway, this is how to make Linux behave in the inferior Windows way, so your time won't shift anymore on your dual boot machine:

a. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

b. Use copy/paste to transfer the following command line into the terminal:

timedatectl set-local-rtc 1

Press Enter.

That should do the trick.

c. Check the status like this:

timedatectl status

Press Enter.

How to undo local time (back to UTC)

24.1. Want to undo local time for your hardware (go back to the superior default way of Linux Mint)? That's easy as well. Simply use this terminal command:

timedatectl set-local-rtc 0

Official bug lists for Linux Mint and Ubuntu

25. Have a look at the official bug lists for Linux Mint and Ubuntu (look for the header "Known issues" or "Known problems"):

Bug list for Linux Mint 19 Cinnamon

Bug list for Linux Mint 19 MATE

Bug list for Linux Mint 19 Xfce

Bug list for Ubuntu 18.04


Want more tips?

Do you want more tips and tweaks for Linux Mint? There's a lot more of them on this website!


To the content of this website applies a Creative Commons license.


Comments