Error 14 at a composite sandwich structure analysis

Hello guys,

I'm currently trying to simulate a 3 point bending test to get the best material arrangement for high bending stiffness in a composite monocoque, while keeping the weight low.

The laminate i strive for is a sandwich structure with an aramide honeycomb core in the centre and three plies of different material on top and on the bottom. 

These are the steps I did so far:

1) I created a CAD model, imported it to HyperMesh, organized the componets (specimen, impactor, support) and meshed them with 2D elements.

2) I created the materials. MAT1 for the impactor and the support of the 3 point bending test, MAT8 for the different plies and MAT9ORT for the honeycomb core. 

3) After that I created the properties. PSHELL with an elementthickness of 2 for the impactor and support, PCOMPP for the plies and PSOLID with the honeycomb material for the core.  

4) Then I created the different plies. 6 with the MAT8 material for the top and bottom layers and 5 with the MAT9ORT material for the core to get a total of 5 elements over the thickness of the core. The material type for all plies is ORTHOTROPIC.

5.1) I created a laminate with the 5 core plies and then did a 'shell to solid conversion' with this laminate. After that I got a new component with 5 elements over the thickness.

[5.2) In a second try I did the 'shell to solid conversion' with the plies of the core which led to the same result as 5.1]

6) I assigned the PCOMPP property to the specimen elements, otherwise the laminate and layers weren't visible over 2D detailed element representation.

7) I updated the laminate with the other 6 plies.

8) Finally I created the load collectors and the load step, an output request for CSTRAIN and CSTRESS

9) I started OptiStruct to run the analysis.

But after a few seconds i got these errors: 

I hope you get my problem and can help me fix it.

Thanks in advance!