[CREO SIMULATE] Advanced spring... inactive

[fstopelli-2]

HI!, Can you help me to understand this message and how to fix it?

It's the first time I see it, 

Thank you

[VladimirN · Accepted solution]

 Hi,

1. Discussion - "Options greyed out in "Mechanism"": https://community.ptc.com/t5/3D-Part-Assembly-Design/Options-greyed-out-in-quot-Mechanism-quot/td-p/392113 

2. Article - "In the analysis definition dialog of Creo simulate 2.0, the nonlinear option "plasticity" is inactivated if a to-ground spring is in the model": https://www.ptc.com/en/support/article/CS94508