ArraynHi sir! Sorry for the delay, in this past few days I was trying to run the model. So I overcome the issue above by clicking in Clear Generated Data in the Model and move on. Then I made the rocker (bell crank) of the spring system and set all the joints in the way I think they should be, representing the reality, but I couldn't run the model, I'm receiving the same message. I already checked to see if all the joints were set in the right way representing the reality and they are, I don't have a clue what's going on. I also changed all the joints to FIXED like you did to see if the model would run and it did, the results were also very reasonable from what we expect from the chassis stiffness, but I think that if we set all joints to FIXED we would not representing reality. Do you know if I can make a chassis torsional stiffness analysis with all joints set as FIXED? Beside, I'm upploading my model as it is today if you wanna take a look, with the joints sets as I think they have to be set. Again, I really apreciate your help mr. Peter! Thank you very very much for your support!nArrayn