I had the same problem last year and despite Andrei's assistence, I was unable to recover the program and database in it's original state. Each time I opened OrangeCD or clicked on the database file, I got the same error message as the OP. I uninstalled and installed the program several times but each time I got the error.

If I recall correctly, I opened the OrangeCDPlayer then used Organize Collection to create a new database. This allowed OrangeCD to open, but it would crash if I then tried to open my old database. So in the end, I deleted by old database (and backup file) and used the OrangeCDPlayer option to create a brand new database and I'm now in the process of doing my collection over again. Unfortunately when it crashed originally I was only had less than 100 titles to enter out of 4066.

Steven