Originally Posted by meemorph

After unmounting you should do a fsck on the partition, that can help to fix the problem. You need developer mode terminal to do it, and you can use the internal jolla mount-sd.sh command to do it right.

open terminal.
type
[CODE]
devel-su
enter password
ACTION=""; . /usr/sbin/mount-sd.sh
fsck /dev/mmcblk1p1
...