Error message "NDofShort= 30 is different from nTotDof= 0 it should never happen." What is

[truckcab]

Hi all Ansys users!
I have the following problem:

I am trying to run a PSD-analysis in Ansys. I have three nodes onto which I apply base excitations. These nodes are master nodes of CERIG connections. Furthermore, I have lumped masses in my model that are distributed by means of RBE3 elements. However, whatever I do Ansys refuse to solve my model. The spectrum matrix is successfully read but then the error message "NDofShort= 30 is different from nTotDof= 0 it should never happen." is repeatedly printed whereafter the analysis ends.

I have established the fact that the error has something to do with the CERIG and RBE3 connections as the analysis works if these are removed. I think I know some workaround so I can probably solve my problem. However, I am VERY, VERY eager to find out why this setup doesn't work since I think it should! Any help in this matter would be very much appreciated, any suggestions to what might be the issue, any hint really. Please see attached sketch of model.

Best regards
PO



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