Static Solver Pause & Cancel buttons flashing

Since upgrading to Solidworks 2016 sp5 I have had a problem when running Static simulations.

When the solver window appears, the Pause and Cancel buttons flash alternately and the simulation does not solve.

Sometimes re-meshing will allow the simulation to run, sometimes i have to re-boot my workstation and hope for the best...

I thought at first it was my old workstation but I just installed a new one and have the same problem.

Any advice?

Thanks!

SolidworksSimulation