Wildcat 4.0 .CFG err

Wildcat 4.0 is working flawlessly except when saving .CFG for any other than 000.CFG? I was under impression that you could create other config files and load them in the program. I’ve formatted the disk but it just keeps getting ERR when trying to save 001.CFG or other than 000.CFG. No other problems on saving or loading .BMP, .BUF or .DAT. Would be nice to have those presets working.