It can mean that your database got corrupted. You can verify that by running a few SQL statements. The easiest way to do so is to install a simple program called DB Browser for SQLite.
- Start the program and in the menu select File > Open Database…` and select your Stash .sqlite database file.
- Then navigate to the Execute SQL tab and run:
PRAGMA integrity_check;- it should returnok.PRAGMA foreign_key_check;- it should return nothing.
If you get something different it means there is an issue with your database. It’s still possible that it can be recovered. You can ask for more help in Troubleshooting.
Another option would be to try using an older backup if you have one.