Fatal Error In Mode Scenario During Update Within Windows Manager While Modifying Ai Or Adding Smth

so i've been trying to modify the ai in a game scenario and adding the wagons so i can couple them but then something is off, when i try to do that, the game crashes with a error that says "fatal error in mode Scenario During Update Within windows manager" it happens to any route like route transylvania v3 for example, and also, i have nothing corrupted in the game

 

Think you always have a problem

 

so?