I got to the city, went straight to the underwear seller, quick saved, bough a couple items, try to quick save again; Error 516.

I have one mod, playing with it for a solid 15 hours without issue until now, Party Be Gone, https://www.nexusmods.com/baldursgate3/mods/327?tab=description
Had a couple others (black dyes and over 9000 weight limit, both removed after patch 3)

I'm running
Windows 11, up to date.
CPU 5950x
128GB DDR4 3200mhz
RTX 3090
Game installed on secondary NVMe SDD, with over 200gb left.

I tried to trade with the seller using both dialog, direct trade with icon, both using controller and KnM. Nothing. One trade, game lock saving.

Game has been rock solid, right until this morning went I finally reach the NPC I was more eagerly wanting to meet. Such a disappointment. I won't be playing until this is fixed.