SAP 2000 error

[catenaryworks]

Hello,

I am performing an analysis of a prestressed cable-truss in SAP. On running the analysis, I obtain an error saying -
"NULL GLOBAL DOF UY IS COUPLED TO A NON-NULL GLOBAL DOF AT JOINT 21
COSINE BETWEEN COUPLED DOF = 0.923880"

Can someone help interpret this?

Thanks

 

[catenaryworks]

I figured this out. It was because I had the analysis set-up to a 3D analysis while my model was 2D. Thanks for responding.