Any one else having GOG Galaxy issues with launching a game after it has been modded?
A couple of my games no longer launch through Galaxy, Fallout included. The exe is still falloutw.exe, but nada.
I modded my Gog Galaxy install of Fallout 1 with Fallout Fixt and it still launches no problems.
Is your Gog Galaxy library installed under C:\Program Files? You could be running into a problem with user account control (UAC); I hear it doesn't like it when installed games get modded, but it only pays attention to certain directories. My library is on another disk and folder entirely so that may be why mine works and yours doesn't.