Error while reading canvas

When I try to open a previously saved Omnigraffle file, it gives a few errors. When clicking Okay, only a blank canvas was shown. This is a super important design file that I need for tomorrow. Anyone know tricks to get it open?

Thanks
Zoe

Error while reading canvas 1/3: *** -[__NSArrayI objectAtIndex:]: index 1 beyond bounds [0 … 0]
Error while reading canvas 0/7: *** -[NSMutableArray insertObjects:atIndexes:]: index 4 in index set beyond bounds [0 … 3]
Error while reading canvas 1/7: *** -[NSMutableArray insertObjects:atIndexes:]: index 10 in index set beyond bounds [0 … 9]
Error while reading canvas 2/7: *** -[NSMutableArray insertObjects:atIndexes:]: index 7 in index set beyond bounds [0 … 6]
Error while reading canvas 3/7: *** -[NSMutableArray insertObjects:atIndexes:]: index 8 in index set beyond bounds [0 … 7]
Error while reading canvas 4/7: *** -[NSMutableArray insertObjects:atIndexes:]: index 8 in index set beyond bounds [0 … 7]
Error while reading canvas 5/7: *** -[NSMutableArray insertObjects:atIndexes:]: index 7 in index set beyond bounds [0 … 6]
Error while reading canvas 6/7: *** -[NSMutableArray insertObjects:atIndexes:]: index 6 in index set beyond bounds [0 … 5]