@booklover6
It seems we are turning in a circle. Logging out/in to restore the database > nickel reads the KSM pngs newly into the database, but does not create all thumbnails > next time you start nickel it wants to create one or several of the thumbnails, for that purpose nickel opens a KSM png > this triggers fmon which shuts nickel down > somehow on the way the database gets corrupted > you log out/in > ...
Let us therefore try something different.
- download the archive from this post, extract start_nickel_test_no_fmon.sh and copy it to .kobo\kbmenu\scripts.
- start nickel by selecting in KSM "scripts" > "start nickel test no fmon.sh"
- if your database is currently corrupted, log out/in to repair your database
- play a little around with the library and the tiles on the home screen so that it is likely that nickel produces all the necessary thumbnails of the ksm pngs.
- powering off the reader by using the power slider
- power on and start nickel as in step 2 ("scripts" > "start nickel test no fmon.sh")
- do your things with calibre (if there is some need for it)
- make a backup of your database (in case the database gets corrupted again, you can just use the backed up, instead of logging out/in)
- next time you start nickel from KSM regularly ("start nickel") everything should work as expected; from this point you can again use exit_nickel.png to return to KSM