Blueprint not visible in play mode after assigning mesh to it

I have an issue I hope someone can help me with.

I have a blueprint of a drivable car in VR, it is made up of multiple elements like the car body, interactable steering wheel etc. Everything works fine standard.

Now this happens:
When I replace the mesh of the steering wheel with a model of my own. As soon as I grab it in play mode, and then release it, the entire engine crashes (everytime).

Anyone have an idea?

Kind regards!
Mayena