Quote from: achow101 on September 23, 2025, 11:42:27 PM

Quote from: takuma sato on September 23, 2025, 05:44:50 PM

saved the wallet.dat file

Please clarify what you actually did, as there is no "save" action.

By saving I meant, I exited 0.8.6 bitcoin-qt, copied the wallet.dat and then pasted it into the hard drive to open it with the knots 29 bitcoin-qt.

Quote from: achow101 on September 23, 2025, 11:42:27 PM

This is extremely unlikely to be a backwards compatibility issue. Looking at the log snippet you provided, it is highly likely that the error is a result of only copying the wallet.dat file. Contrary to popular belief, the wallet.dat file is not the only file you have to copy when copying a wallet from one node to another. You also have to copy that database folder.

This is especially true for older versions of Bitcoin Core as shutdown did not always compact everything into the wallet.dat file. Furthermore, copying the wallet.dat without unloading the wallet (or stopping Bitcoin Core) will result in data loss, and therefore detected corruption, because the log files in the database directory contains data before it gets committed into the wallet.dat file.

This behavior is also one of the reasons that we wanted to move off of BDB. SQLite can be configured to specifically not do that and to always write into the wallet.dat file.

I've never heard you needed the chainstate files. I may or not have a copy of the chainstate files of the old Bitcoin Core install where the actual wallet with private keys came from. It may still be there in some old Windows install of Bitcoin Core. Im assuming there is a way to salvage the private keys from the wallet.dat without chainstate files otherwise I would be screwed.

Im hoping this is a particular thing that happened by doing this on a Tails live session, perhaps something went wrong there. I will try with the real wallet files on the airgap computer just in case, if I get the same error then im going to need some good ideas in case I cannot find the chainstate files from whatever install the wallet was last used in. Would actually be insane you need these files to backup your keys but I will try to find them anyway.