This issue could be associated with corrupt materials.
Please try the following workaround:
1. Copy and paste the material into a new custom material library (.sldmat).
2. In the material dialog, change the 'Default failure criterion' drop down menu option to 'Unknown', then Save the material
3. Reapply the material to each appropriate component in each study, directly through the Apply/Edit Material command in the Simulation Study Tree (not by allowing the material to carry over from SOLIDWORKS).
Please let me know if it helps.