This is a repeatable bug, happens EVERY single time I go to the options menu and go back to the game. The regular map (not the cloth map is there), but all units, cities, etc. are gone and the game slows to an absolute crawl just moving the map around.
I normally play with cloth map enabled, b/c it's easier to track units. When returning from the options menu, however, the cloth map is no longer enabled or visible. The same problem happens if I alt-tab and then return to the game.
This bug essentially means that I am unable to save or load games, barring exiting the game every time. Which is frustrating, because this game takes FOREVER to load.