Unfortunately, the only thing we can say to this is that if it's that important, you should do a manual save immediately after entering it and not depend on the computer staying functional until it shuts down and tells KeePass to do the save on its own. As you found out, the chance of this "save just before shutdown" sequence failing is miniscule but not zero.
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Hello
My computer restarted and the last transaction I made on keepass was not saved. It was a very important password, is there any way to recover it?
There is no way to recover an unsaved password. :(
cheers, Paul
Unfortunately, the only thing we can say to this is that if it's that important, you should do a manual save immediately after entering it and not depend on the computer staying functional until it shuts down and tells KeePass to do the save on its own. As you found out, the chance of this "save just before shutdown" sequence failing is miniscule but not zero.
Use a plugin like KPSimpleBackup.
This will automatically save the database after you made changes.