I have the same error, I've edited my project XML to delete the conflictive events, but now I've read this, what I can do to solve the problem? I'm working with urgeny and I can't do anything.
Edited: To fix the problem just open your .caproj with textpad and find "sounds-folder", replace all the "file-folder" with "sound-folder", same with music folder, replace "file-folder" for "music-folder" now my project opens and works like a charm