I can give you a list of my mods, but as I said I've disabled and actually uninstalled all of them and the problem still persists.
I have to admit, I couldn't find anywhere resembling a Debug folder to put your file, but the main screen in FireTuner gave this error every time I clicked the button
ProductionPopup: WARN Turn 0 GetHelpTextForPromotion: stat data is nil for PROMOTION_IGNORE_TERRAIN_COST_NOUPGRADE!
Runtime Error: C:\Users\Shayne\Documents\My Games\Sid Meier's Civilization 5\MODS\Communitas AI and Tools (v 3)\Tools\TooltipWriter\InfoTooltipInclude.lua:166: attempt to index local 'section' (a nil value)
Lua log seems to say the exact same thing, but I've got my logs here for you still.
List of mods I (usually) have installed, aside from CEP, though I don't always use them all at the same time.
Update: As I was typing that list, I remembered that as part of putting in the City-State Diplomacy mod, there's an option in Cat_Options.sql for Citystate Diplomacy Mod Compatability. I went and switched that back to off, started a new game, and behold! Everything worked fine. Re-enabled it, put CSD and related mods back into the game, and it stopped working again. Looks like the problem's somewhere in there, though it seems to be on the CEP side, as the same problem occurs whether or not CSD is installed. Guess I'll just remove CSD for the time being, but I hope whatever the problem is can get fixed sometime.
Update 2: Nevermind, I put back in all my mods minus CSD, started again, and got the same problem again. Now the error in FireTuner is this:
Runtime Error: C:\Users\Shayne\Documents\My Games\Sid Meier's Civilization 5\MODS\Communitas AI and Tools (v 3)\Tools\TooltipWriter\TW_Init.lua:470: attempt to index global 'GameInfo' (a nil value)
Got rid of everything that used the modified DLL, and it works again. On a related note, the InGame Editor doesn't want to work at all either, and every time I click to open it it pops up an error message referencing a line somewhere in Communitas AI & Tools. But not having IGE isn't a game-killer for me. I believe the error it gives is:
IGE_Window: C:\Users\Shayne\Documents\My Games\Sid Meier's Civilization 5\MODS\Communitas AI and Tools (v 3)\Tools\TooltipWriter\TW_Init.lua:123: attempt to index a nil value