RE: RAM Concept - Vibration - Error message

I reproduce the error in another model. I will report the problem to the development team. In the meantime, the following steps should resolve the problem:

1. Re-generate the mesh.
2. Click on Criteria - Calc Options - Vibrations tab and change the Stiffness Matrix Setting.
3. Click on Process - Calc Load History Deflections to run the load history deflection calculations.
4. Click on Process - Calc Vibration Analysis to run the vibration calculations.