I had a backup of my wallet.dat a few years ago, which was encrypted for sure.
But when I try to reload it now, it shows 0 balance after the whole blockchain sync, and it is weird that the option of encrypt wallet is available.
Whether I try the bitcoin core 0.14.2 or the bitcoin 27.0, it turns out to be the same.
The wallet.dat might be corrupted because I might copy it while the bitcoin core was running.
I tried pywallet to dump the private keys but the none of them is the right one.
Also I tried btcrecover, and it said the wallet.dat is unencrypted.
Now I don't know what else to do but to ask for help, guys please help!