Trying to open a .kdbx database with correct password gives the following error "Unable to open the database. Wrong key or database file is corrupt". However, it does work on OSX. Repairing does not fix the issue. I remember also having few random successes before but that's about it.
I had the same error. This answer on GitHub was the solution for me:
I have the same problem, and somehow it is corrupted on every copy of the file i've got.. How is that even possible? I know it is the right password, as i have used in 10 years. And i got a lot of backups, but none of the backups work.
Can it be the program?? any updates that could make it useless?
Edit: It is only the latest copy that is corrupted, the older ones had a different password :D