I ran into some problems with BTS crashing and its CivilizationIV.ini file losing most of its data every time I start BTS, and decided to uninstall and reinstall all of Civ4 (after saving replay files and old CivilizationIV.ini files). I've got vanilla and the 1.61 patch reinstalled, game play is fine except no Worldbuilder button (I had checked the Lock Modified Assets and Random Seed boxes when starting a game). The CivilizationIV.ini file has only the following info; something is causing the game to not generate a complete ini file.
(CONFIG)
; Enable Trilinear Filtering for the Minimap
MinimapTrilinearFilter = 1
; Enable Tree Region Cutting
CutTrees = 1
; Allow Camera Flying
AllowFlying = 0
; Enable Quick Slide Show Transitions
PopSlides = 0
; Set to 1 to automatically end slide show
EndSlides = 0
(CONFIG)
; Enable Trilinear Filtering for the Minimap
MinimapTrilinearFilter = 1
; Enable Tree Region Cutting
CutTrees = 1
; Allow Camera Flying
AllowFlying = 0
; Enable Quick Slide Show Transitions
PopSlides = 0
; Set to 1 to automatically end slide show
EndSlides = 0