Build 107 I can recreate this problem using either the 370Z or GTR at Mills track. (I haven't tested other mods and tracks yet.) Start a practice session in dry weather, when it starts raining request pitstop. In the pop-up pit menu tell it to change all 4 tires to wets. Pull into the pits. As soon as car comes to a complete stop in your pit box the game closes back to the Launcher and you have a classic Windows message that says rFactor2 has had a problem (or maybe it says stopped responding, can't remember exactly). If I start the practice session on Wets it lets me change back and forth between wets and dry tires without problem, but the tire wear pop-up starts acting weird and can show all tires as gray (stops show tire temp colors and tire wear progress colors).
In fact the game crashes with every track and car when you try to change the tire compound. ISI is working to fix it with the next update. More info here Game-crashes-during-Pitstops-in-wet-race
