Could not understand address in import file

[sinisterdev]

So, I found a really old doge wallet (created around 2017) and I think I know the password, because when I enter it and click "Unlock" It doesn't give any error, but when I finally click Import private keys I get this error: The private keys unlock failed. The error was "Could not understand address in import file".

Any help?

[doge2021]

maybe it is not a multidoge backup? what's the file extension? you may reach btc recover on twitter to help you, good luck