I am trying to install this add on but it is stuck on install screen. It just says "Welcome to Doom BFA Installer" and it does nothing else. I have the Doom 3 BFA edition from GOG.

If anyone can help I would appreciate it.

I found the addon at PCgamingwiki.com

Thank you!

Did you try using the extractable zip file instead of the installer? Extract the archive and you will find two archives inside it (one 32-bit and one 64-bit). Extract your desired one over the top of the Doom 3 BFG Edition installation and then move the files from base_BFG into the base folder. Then that's it, just run the DoomBFA.exe to start it up.