Well, good news: I downgraded to P3D 4.1 and, guess what, it was crashing on me too, even under the debugger so, I was able to find the issue very quickly and yes, I didn't noticed we had some code which was still related to the 4.2 SDK indeed.
I think it's fixed, and is still backward compatible with 4.1 so, just run Live Update again, and it should work.