I checked the sdcard – it is not currupted.
Of course burning new image would be an option but as I dedicated lots of time to set it up I would like to avoid doing this again.
for troubleshooting steps you might consider:
1. I deleted the mountpoints in /etc/fstab
2 I added one of them with m2p gui – success
3. I checked /etc/fstab modification date after adding -08:51
4. I pressed delete on the newly added mountpoint in m2p gui at 08:53, for several seconds icon of turning gear apears – then it refreshed – feedbacj no message if removing was succesfull or not – just a refresh where the mountpoint is still present
5. INTERESETING – there were no changes in /etc/fstab but modification time of /etc/fstab changed to 08:53 so the time when I pressed „delete“ in gui
So to me there is no corruption but a bug in the file parsing /etc/fstab
