Game Crashing

[Terminator]

Hey Guys I am facing this issue when I select a secondary person in the game like allied soldiers and their captains and try to run and engine or any other thing that has to be done with holding shift the game crashes as soon is a hold shift and hover over the thing please help me out its really frustrating

also Idk why but I saved a game it a point where the game crashed after and now when I load the game just crashed