Undefined value found // Hyperelastic parameters

Here we go again: When it comes to solving im getting anther error wich is quite frustrating.
It says: Undefined value found. Detail: Undefined value found in. The equation-residial-vektor.
There are 51993 degrees of freedom provide NaN/Inf in vector for variable mod1.u.
(0.8225,0.0045,0.00555), (0.8225,0.0045,-0.001), (0.817488,0.0045,0.00555), (0.819994,0.0045,0.00555), (0.8225,-0.001,0.00555), ...
Feature: Stationary solver 1 (sol1/s1)

This continues for mod1.v and mod1.w as well.

Another thing wich i'd be interested in: Are there any typical parameters for silicone rubber hyper elastic model already in the internet somewhere? I got no material to make a new stress strain curve and calculate the parameters for Mooney-Rivin and so on ;)

Im looking forward to finally solve this someday ;)

THanks!