I Installed Bitcoin Core v25.0.0 and restored my old wallet backup made in 2014 (with bitcoin core version of 2013) successfully. The wallet is shown, status is encrypted and locked.
Trying to unlock the wallet with the passphrase results in this error:
BerkeleyDatabase: Error -30974, can't open database wallet.dat (code -1)
The backup was made on a Linux machine, the recovery on Windows.
Does anyone have any suggestions on what may be the case and how to resolve this?
The error code -30974 indicates that the database system (Berkeley DB) is having some issue with opening the database file and thinks that it is corrupted and that a recovery procedure needs to be run.
One way to try to resolve this is to use the bitcoin-wallet tool's salvage command. Note that this is essentially a last resort tool as salvaging is known to cause issues for non-corrupted wallets. I recommend that you ensure that there are backups of your wallet prior to using salvage.