If you are facing errors opening designs after the last update of StitchBuddy HD, enter its settings and turn "Empty Cache" on to rebuild the gallery without data loss. This procedure is also mentioned in the FAQs of its integrated help to correct wrong entries in the gallery.

Because of this issue I have just removed StitchBuddy View from Apple's approval queue and I will provide a bugfix ASAP. Sorry for the inconvenience!

Update (2013/03/08): I have just submitted StitchBuddy HD / View v2.5.2 for Apple's approval, correcting the mentioned issue, and even filed an "Expedited Review" for StitchBuddy HD, to make it available as fast as possible.