On an old version, 0.5.18 on Windows 64 and I am trying to load a wallet with a .wallet file from about a week ago in the rolling backups folder, but I keep getting an error, "Could not load the wallet file.......Error message was "null."" Do I need to put the file in a specific location or do I need to update my client first? I have made copies of all of my wallet files.

I'm not sure what other information would be useful to you, but let me know what else you might need to know and I'll provide it. I'm very new to this and obviously it's been a while since I messed around with it since I am on such an old client version. I'll be updating as soon as I get this all figured out.

Thank you in advance.