Hello, There are lots of issues here. I am trying to simulate a electronics chassis on a tray with LORD type isolators with the spring model. First, how do you make them visible in results. I cannot seem to see them. So run a static "check" simulation (1 G in one direction) and I get some results. The reaction check out, etc. I run an eigenvalue extraction. I get the model shapes (without springs) and they seem reasonable. I run a random vibration and I get the fatal error, saying that I have an unconstrained degree of freedom. The message continues that I should run a constrained Modal Analysis with rigid mode search to see the unconstrained degrees of freedom. Well, I did that and 1) I didn't have any rigid modes. (with the rigid mode option on and the lowest frequency to start the search at "0" Hz. HELP. Any suggestions???