Quote from: aintnobody on January 08, 2021, 12:12:43 PM

I have wallets created with Multibit Classic (specifically, v0.5.14).

Shortly after creating my wallets, I added passwords to them. Later, on one wallet, I changed the password.

Flash forward some years and these wallets do not unlock even though I am 1000% using the correct password.

When I compare these wallets to other Multibit wallets (without passwords) by File Size, they are much smaller.

When I attempt to unlock these wallets with the correct password I receive the error "Provided AES key is wrong" whereas all other strings return "Could not decrypt bytes"

Since the software can distinguish between a correct and incorrect password yet cannot make sense of the contents, I can only conclude that this means the wallet is corrupted, and that the corruption occurred in the encryption process and not on the filesystem afterwards. I have tested HardCorePawn's utility on GitHub (https://github.com/HardCorePawn/multibit_recovery) and similarly I receive different output when entering the correct password, proving that the password is right, but the contents are corrupt.

This is a very big deal. We're likely talking about an eventual 100's of millions if not billions of dollars in BTC between all the Multibit users who will have been struck by this issue, many of whom probably still hold out hope of one day 'cracking that password'... not knowing it isn't the password that is the problem.

I'm looking at broken software that corrupts precisely the wallets you most want to protect, simply by using the software as was intended. And as a modest person and true believer, I trusted that one day I'd be able to come back to those wallets, but now I see.

My question is, what now?

This is a pretty gutt-wrenching thing, my heart goes out to everyone else facing the same. I just hate the feeling of 'well, that's it, there's nothing I can do'...

This is a bug of the old wallet. unless you have made backup, there is low chance to recover it as the data is corrupted. if you have other files, there is still chance to recover it.