When Importing photos using Picasa, you may see this error:
An error has occurred while attempting to import. Either the source is unavailable or the destination is full read only
This page lists some possible solutions or workarounds.
Instead, import pictures using Windows File Explorer - see "Method B" here: How to import photos and videos using Picasa or Windows File Explorer
Be sure the folder you are trying to import to does not already exist on the destination drive. Take a CAREFUL look at the "Import from" and "Import To" settings. If both locations are the same, change the "Import To" to another location.
Be sure you're not trying to import into the source.
If something is wrong with one of the photos you are trying to import (a corrupt image, for example), you can see the error message. Manually remove the image.
Is your source drive getting full? You may need a larger drive.
See if the camera settings are set to use its second memory card as a "back-up." Picasa may not be able to import into a second memory card.
In Picasa, click Tools > Options > General tab. "Save Imported Pictures in" then browse to a folder on your computer where you want pictures to import into. Click OK.
In Windows File Explorer, right-click on the destination folder and click "Properties." Make sure that it's not set to "Read Only"
Disk space on your C drive may be getting full. When importing, Picasa saves a temp copy at the following location; see if clearing the temp folder helps:
C:\Documents and Settings\<username>\My Documents\My Pictures\Picasa3Temp (This is a path from an older version of Windows)
Possibly the Windows 10 path is here: C:\Users\YourUserID\Pictures\Picasa\Picasa3Temp
Or this path?: C:\Users\YourUserID\AppData\Local\Google\Picasa2\tmp
Picasa on Vista has some issue with seeing RAW files when the camera is connected in PTP mode (or "Normal" mode for Canons). Try changing the USB Connection Type setting to "Mass Storage"... also make sure you have "RAW" selected under Tools > Options > File Types. .
Files over 10,000 pixels on one dimension will have problems importing. Manually import those.
Use the import function in Windows photo gallery.
Connect to the computer via USB (PTP mode) and open Windows File Explorer. Navigate to Computer\<USBdrive>\Internal storage\DCIM\.thumbnails. Delete everything in this folder.
If you are connecting the camera to the computer and using the camera drivers during the import, check to see if there are updated drivers for the camera.
If importing from a camera with photos on a memory card, remove the card and insert the memory card into a card reader.
If you're using a USB memory card reader, try attaching it to different USB port.
Uncheck "Exclude Duplicates" in the import screen.
If you are using the scanner to import, turn off the scanner then turn on the scanner.
Make sure the scanner is still using a supported format like JPG. Picasa doesn't support B&W JPG so make sure you are scanning in Color or at least Greyscale.
Use your scanner software and save the photos into a subfolder inside the Pictures folder. Picasa automatically "sees" anything written into a watched folder, if Picasa's Folder Manager (under the Tools menu) is set up to watch the Pictures folder and subfolders.
Reinstall Picasa. Make sure you're using the latest version.
Rebuild your Picasa database. See Method B
Restart the computer.
Import doesn't work if you have a screenshot on your iPhone which is recorded in PNG format.
Bring up iPhoto on your MAC. Do you see blank thumbnails in iPhoto? If so, delete these photos in iPhoto and then try importing the iPhone 4S photos.
Videos taken with iPhone 4S can cause the import process to stop. Manually save the videos to your computer, then delete them from the phone after you are sure the videos are saved and backed up.