1. The mission editor crashes if you do not have a previously saved mission for it to open with.
2. Similarily, If I were to move or delete the last mission built, the ME will crash on opening until I either restore that mission to it's original location or delete the AHEDMISS.cfg file.
3. Often, the ME will crash during resource building if you have selected anything other than the default setup file (tables) This happens even when the tables contain the correct mission planes.
4. There are crashes both on and offline. I have not been able to narrow them down to specific causes, although some offline missions that crash will run without crashing, if all "attack" segments are changed to another type such as "patrol" or "cruise"