As per the title I am experiencing an "Unknown Error" when trying to purchase or trade with any vendor and a "Cannot read property 'StackObjectsCount' of undefined" error when trying to insure any item.
When trading item for item, the item(s) required for the trade disappear from my inventory, the unknown errror message pops up and the vendors item will not appear in mine. When buying with money nothing happens, I dont lose money and I dont get anything.
The errors only appear after a few hours of play so I'm not really sure if its a mod problem or not.
My best guess if it turns out to be a mod problem though is its either something that I have in my inventory or me having too much in my inventory due to kiki-BiggerStash increasing my inventory size beyond standard game limits.
The fact that it only happens after quite a while into the save makes it hard to test if individual mods are causing it.