That's strange, it shouldn't matter what you have in the MODS folder until you click the MOD menu.
1) Close the game.
2) Go to C:\Users\[username]\Documents\My Games\Sid Meier's Civilization 5\cache and delete every file and folder inside (but not the folder cache itself)
3) Delete everything in C:\Users\[username]\Documents\My Games\Sid Meier's Civilization 5\MODS folder.
4) Manually install prehistoric era reborn, enlightenment era, future words and the patch. Make sure that all mods are the latest version. Links are in the first post of this thread.
5) Start the game. If it works, skip step 6 and proceed to step 7
6)
Enable logging then run the game again, and after it crashes post the log files here.
7) Now that it works, slowly add the mods you want, 1 mod at a time and test each time. See when it breaks.