"This score has become corrupted and contains errors"

Every time I go to save this score I am getting this message: "This score has become corrupted and contains errors". I looked at the measures and the part it says in corrupt and it looks just fine. There are 3 beats - on both the part and the entire score. But I figured I might as well try - I deleted the notes and re-entered brand new - still get the same message. Is there anything else I can try?
Thanks!