Why won't my chassis mesh?

Hi,

I'm a manufacturing student designing a chassis in solidworks and I need to do an FEA analysis on it for my report, but since I haven't taken any FEA courses and have little experience using solidworks simulation, I'm having trouble getting my chassis to mesh. I've attached the file. Can someone tell me what I'm doing wrong? Once I can get it to mesh, I know how to fix certain points and apply points for impact, torsion, etc.

Thanks

SolidworksSimulation