Potentially corrupt microSD Card can occur when a linux system is rebooted without running shutdown or reboot. This usually occurs because of a power cycle.
Running the following command
$ sudo dmesg Grep | fsck
FAT-fs (mmcblk0p1): Volume was not properly unmounted. Some data may be corrupt. Please run fsck.
The way to repair this is to do the following:
Open a terminal window and ssh into the raspberry pi and run the following commands
$ sudo umount /boot
$ sudo fsck.fat -V /dev/mmcblk0p1
fsck.fat 4.1 (2017-01-24)
0x41: Dirty bit is set. Fs was not properly unmounted and some data may be corrupt.
1) Remove dirty bit
2) No action
? 1
Starting check/repair pass.
Starting verification pass.
Perform changes ? (y/n) y
/dev/mmcblk0p1: 484 files, 73404/489976 clusters
$ sudo fsck.fat -a /dev/mmcblk0p1
fsck.fat 4.1 (2017-01-24)
/dev/mmcblk0p1: 484 files, 73404/489976 clusters
$ sudo mount /boot
$ sudo reboot