Found an easily reproducable bug, where if you combine multiple objects with holes, wings will crash (Writing the crash dump, program continues, thankfully).
1) Make two cubes
2) Make a hole on each cube on one of their faces
3) Combine the cubs
The crash dump is attached.
1) Make two cubes
2) Make a hole on each cube on one of their faces
3) Combine the cubs
The crash dump is attached.