Encrypted SD card failed after S5 restart
Solution: Follow the steps outlined by Colbe here but format the SD card with GParted on the computer and then format it again on the Android. And leave out step 5.
Likely cause: a missing .MetaEcfsFile file.
Also GParted showed just the &quot;boot&quot; flag for the SD card partition: no &quot;lba&quot; flag.