The map is normal size, the game era has entered modern America, the speed is normal, single player game, specifically I was stuck at 239 turn, never able to get to the next turnremotecache.vdf

Had same problem at turn 133. Endless turn pending. Pressed ESC, then saved game. Reloaded save and was able to continue with game. At least it's not as bad as Endless Space 2 where you can't continue!

Same issue