run- up analysis-rotordynamics-ansys

Dear all,

I want to do a run- up analysis for a rotor in ansys. The rotational speed change from 0 to 5000 rpm

In ansys help is explained:

nlgeom,on !! so that the gyroscopic matrix is updated

But because my model has Combin214 element, the nlgeom make error and solve dont run.

when I remove combin214, I dont get error.

I changed combin214 with matrix 27 but same problem.

In an example in ansys is used combin14. but my model is 2-D axisymmetric analysis and I think combin14 in not good element for modeling bearings.

How can I solve this problem?