This is how I do it, but it doesn't work! I unlocked it without synchronizing the blockchain.
Those commands will work whether your node is synchronized, disconnected or not.
Based from the hint above, do you somehow have a
disablewallet=1 entry in your bitcoin.conf file or as an additional start parameter in your shortcut?
Because disabling the wallet will make 'wallet RPC commands' like walletpassphrase disabled.
After I downloaded the Bitcoin core wallet, no other operations have been performed. If I disable it, how can I find out? Then how to unban it? I'm a novice, please!