Assembly falling apart

Hello all

I have a rather simple assembly with just 5 parts. I'm trying to run a motion study in which a motor drives a slot wheel, but the whole assembly falls apart within one second into the simulation. Does anyone know why this might be happening? I've already tried the highest contact resolution, but it still falls apart.

Here's a short clip of it falling apart: Video

Any help appreciated.

Thanks

SolidworksSimulation