Mesh information not available

All,

I have a fairly simple assembly with 44 parts.  nothingfancy. all solids.  I create a mesh, and the meshercompletessuccessfully and you can view the mesh, and no warning orerrorindicators are on the mesh portion of the tree.  However,whenI right-click to run analysis, I receive a pop-up saying,"MeshInformation not available", and a red X appears inthe tree.  

This also happens when I use the "Run analysis aftermeshingcheck box".

Note:  This does not happen every time.  

Please explain.  If needed I may be able to post themodel. SolidworksSimulation