The solution matrix is not factorizable. This might be caused by an unconstrained rigid body motion or by over constrained degrees of freedom due to multiple linear relations at at least one node
Hi @l00130231!
This is not a detailed enough description of your problem and the matrix issue can have several causes. Do you mind sharing the project with us here in the comment section and make sure it is public? We can proceed from there.
Best,
Jousef