I would suggest wait for Andrey on this.
If it cant wait - and maybe you have to re-read in everything again.. read on:
I have also got errors, but after several restarts it works again.. I think its related to the database.
I have also tried to remove everything and re-read in everything. But that takes a loong time..
Are you sure you did not change any folder name ?
Have you disconnected drive ?
have you selected the NAS or share in “file explorer” if its a network drive, so Tonfotos can get access to the share?