CREO7.0.9.0: Unable to select Plasticity in Static Analysis with Elasto-Plastic Material definitions

Currently I have a contact model that consists of two separate bodies. One body is fully fixed and assigned a linear elastic material with steel properties. The second body rests on top of the first and has a fully defined elasto-plastic material. This was defined using developed test data. My problem comes when I am trying to enable "Plasticity" in the static analysis. The option is completely greyed out and unavailable. The material is both assigned to the model and to the correct body. Has this issue been reported previously or is there something I am missing? 

I have tried a variety of solutions such as assigning all bodies the same elasto-plastic material, suppressing features that could cause issues (grounded springs/Links). Neither solution yielded any results. Even when using the elasto-plastic material definition I receive the same error seen below. Note: EP is shorthand for elasto-plastic for my naming convention and the material it is referencing does have an EP material definition. 

** Warning:

           The yield condition has been exceeded for the material(s) listed
           below.  You should consider using an elasto-plastic
           material, if applicable.
EP_A357

Any help would be much appreciated. 

Thank you, 

Evan