import CAD files (from ProE to Comsol)

hello,

I've tried comsol and I tried to import a CAD file in step format (*.STP) created from Pro Engineer.
Comsol starts to import, and stops at 50% of the loading...nothing happened...
I don't know why?
My ProEngineer file is about 9 Mo.. Is there a problem with this?
Do you have any idea how I can import my file at the end?

Thanks.