First make a copy of the original file and store it somewhere safe. Next please use a hex editor to open the file and see if you can find any public/private key pairs in there. You could then import these into another wallet like Dash Electrum to recover your funds. You can also try to rename the file and open it with Dash Core, but I'm not sure if you will have much luck there. Feel free to send me a private message if you need help with any of this.