HELP! My Character Animator Project Crashed and won't reopen

For those following along, this turned out to be a very strange (and honestly kind of disturbing) case. I don't actually work on Character Animator day to day anymore, but try to reply when cases like this come up.

Basically what happened here is that the project file was valid at the lowest level of format validation. The rope format is only changed by appending new records and all the records in the file were valid. The problem was that there were some records and that level of invalidity isn't detected by the automatic repair mechanism. Usually automatic repair reads until it its a malformed block and truncates the file there. This generally works really well, but in this case the blocks were all valid but when it went to interpret them as a project, it failed because there were a few holes. So I found the last point in the file where the content was complete, truncated it at that offset, and then it opened fine.

I haven't actually heard back from Matt to confirm, but I think the project will work. It took me a few days to get time to dig in and understand what had gone wrong. Hopefully it wasn't too late. 😕😕 The disturbing part for me is that this would seem to indicate a hole in error handling or a filesystem that sometimes silently fails to flush writes. It's extremely surprising that it managed to only write valid records but not all of them. 😬

A bug like that was discovered, but it was an earlier version and was believed to be fixed.