Thanks for the report. If this is indeed bugged, I can unfortunately not fix it, as I am no longer active in Rome 2 modding. But there is another version of this in my workshop.

After some testing, on a new save one thing I can report is that the diplomacy screen has been bugged, all factions trade icon in diplomacy is now red. You can still initiate trade with any eligible faction through initiating negotiations with a faction but from diplomacy overview screen it appears as if no eligible factions can be traded with. ( the two way arrows icon which is usually grey if eligible are all now red ineligible.)