Provided private key is not valid

So I successfully obtained a wallet using my private key.
Just wanted to log in and forgot my password. I wanted to repeat the whole process (create new wallet with a private key) but now I’m getting an error “Provided private key is not valid”. It has 64 symbols and I used it to create my existent wallet.
Help please?

Valid key has 64 lengths, digits and letters (only allowed a,b,c,e,d,ef)