Paintshop not working when I hold shift and click on the car

[RaymondYouTube]

I added the paintshop app in Assetto Corsa. However, after I load onto a track, when I try to hold the shift key and click on the car to paint it, it doesn't take me to the paintshop. I tried both shift keys and I've been clicking on every part of the car. No dice. And I can't even close out of the paintshop app. I tried clicking on other apps like the Pure Config, Pure Planner, Traffic Tool, and and they don't pop up, the paintshop app won't let me click the other apps and it won't let me close it. So to fix it, the only way for me to close the app is to remove the paintshop app. What is causing me not to go onto the paintshop on the track? Please help me.