Would you recommend deleting the door? It won't block the way to the building?
Install the fix in the first post - as it says there, it works on new games or those where you haven't visited Beregost yet (as you say you haven't).
If you don't know how to do that, copy and paste the code in that codebox into a file named Setup-BeregostFix.tp2 and save that in your BGT folder. Copy and paste another mod's .exe, renaming it Setup-BeregostFix.exe. Double-click on that and install as any other mod.
Would this method work for BG Easy Tutu aswell? (I have the ToB version) Or is the whole code thing & .tp2 / .exe method suitable only for BGT?
Kudo's to you ASC64 for solving this, if the BG community could give out nobel prizes I'm sure you would deserve to get one