I know that messing with the VNAV altitudes can occasionally cause a game crash, and that the issue has been adressed on here, but i went ahead with this post bcs what happened to me seems like too much to be a coincidence, and hey, idk, this might help the devs fix the issue :)
From an hour ago to now, i have made 4 FPLs, for 4 flights, to try and fly to EDDF from LIRF and LIML respectively. On every atempt i made an FPL, took off, and as im climbing i start changing the VNAV altitudes in the STAR, and on all 4 occasions, my game crashes.
The crashes did not happen when editing any specific waypoint so in my opinion this could be an issue with the STAR at EDDF, since i just tried re-doing the exact same chain of events, only for an FPL to Munich, and its all working fine.
The STAR and APP in question are: EMPA4E, I07RZ
Hope this helps!