@CannibalVox This is all I could come up with. I'll make sure to not delete upcoming corruptions on 1.7 so we have more to work with. It does not include the "can't open questbook" corruption due to null teams as I hooked the save handler to clear them out before the save.
http://www.mediafire.com/download/86faeky9mme5t1l/HQM-SaveCorruptions.zip

@CannibalVox here is an up to date one. Already happened with 2 different packs within the last 5 days: http://collaboration.mym.li/issues/463
The line number matches with the repo:
https://github.com/lorddusk/HQM/blob/master/src/main/java/hardcorequesting/Team.java#L908

Closed due to no longer supporting 1.7.10, please check if this problem persists in the latest 1.9.4 version. Saving, loading and networking are rewritten for 1.9+, this should resolve this issue