Can't modify collision??
I've came across one problem, when I've wanted to change collision model on car trailer (as in it's original state was unsuitable for it's purpose, doors were breaking, cars were flipping over)
I am newbie in 3D programs in general, but I've managed to change pretty much anything except the very collision model. I believe I've just overlooked some silly setting, just take a look on screenshot
Probably some setting I am not aware off, forbids me to select and change the collision for this part of the car trailer.
Could anyone give me advice how to overcome this, please?