I have already tried re-installing BGII which cleared out all the mods I was using, but the game still crashes. I am, pretty much out of my depth when it comes to looking for scripting errors in the game codes.
I tried loading an earlier save, entered the pocket plane and then exited successfully. So I began to wonder if it had something to do with where I was the first time. So, out of vexed curiosity I loaded up the earlier save, went into the bar to where I was when I entered the Pocket Plane previously and did the same. Then, when I tried to leave, I left! No crash, nothing. So thinking I had somehow fixed the glitch, I tried my main save again, and again, it crashed on exiting the plane.
so, here is what I know.
It isn't a mod, for even with all mods removed the game still crashes trying to leave the Pocket Plane
It isn't based upon where I was in Saradush, as recreating the departure doesn't recreate the problem.
It seems to be, that ONE particular game save, but I have no idea why