Seen this bug report in the MGSO v3.0 private test :
chaosapiant666 :
think I found the cause of the barter/crash bug! I believe it is tied to the Animated Chests mod. I unchecked that ESP, and for the life of me could not get Arrille to crash on me during the barter menu. Maybe there is an already updated version of this mod? I know it was just released not too long ago.
Edit: So, I removed the animchests.esp and the game no longer has this bug. I installed the newest version of Morrowind Animated Chests, and the bug returns. The ESPs have different names, but i'm sure it's the same mod, and that mod seems to be what is causing the issue. Can anyone else confirm this?
I actually may have had this bug a couple of days ago. Can't say for sure because I had some other newly installed mods too that may have been the culprit. Anyway, my game kept crashing when I would barter with the pawnshop in Balmora. I haven't had any crashes so far today with this new version though.
I am very sorry to report that this issue is confirmed on a completely clean install of Morrowind. No mods, no replacers, no patches, and no MGE. The first time I bartered with Arrille, I had no problem. I left the cell, returned, and selected "Barter" again. I canceled out of the barter and as soon as I clicked "Goodbye" the game crashed. It does it every time with nothing in the Warnings.txt. I don't find it particularly rare to cancel out of a barter menu, so this might be a serious problem. I did not experience any issues with Spells, Persuasion, or any other dialog option, only "Barter".