I was only told about the Tradition Finisher last time, but I can fix that for the next update. Sorry, I meant to reply in PM, but things got away on me. No, CID doesn't have support built in for that, but, funnily enough, I'd planned to add it in the next update, as my upcoming Bhutanese civ has a unique Great Prophet. I do not know a way for CID to override your ProductionPopup, no, other than to reference your mod's ID - but this would cause other problems. So I would recommend excluding this from your mod if you want to have support for CID, and wait for the next CID update for this fix to be incorporated. Difficult to tell without callback. Could you please set EnableLuaDebugLibrary to 1 in your My Games/Sid Meier's Civilization 5/Configs.ini file, reload that save, and report back with the Lua log. It should then trace where that error is being triggered specifically.