Action house not allowing to sell- still not working

[Poizana]

WoW Freakz link:
Character name: Poizan
Bug description: I can't sell anything on the action house. The error I get is "Interface action failed because of an AddOn". I have no addons, 0. Tried to delete the interface folder and start the game again,same problem. I tried to delete cache and unstuck from the site, lowering the price and waiting at least 10 seconds before pressing the "create action" button. I asked around and some others had this problem resolved after the restart but not for me. I still can't sell any item, even if it's not available on the action house (so creating a fresh action).
Proof: https://imgur.com/DaiGj3v
https://imgur.com/yATUgxL

Later edit: found a temporary solution on the internet, empty your main bag- the backpack and put the items you want to sell in it, then sell them from the backpack. Doesn't work anymore, pls help.