Emperor
Subscriber

I often had this problem in my contact analysis. Most of the time it was a contact that became very degenerate. If it does not converge you can display the Raphson newton residuals and see where you have a problem. Once the contact is detected, you can then correct it in several ways: change the contact stiffness; change the contact detection to nodal to target (by default it is set to gauss points), increase the mesh density on your contact area.

I also learned that in a good nonlinear static calculation you should always check the penetration, this one must be small in front of the dimensions of the structure.
( I am still a trainee on the ANSYS tool and I am still developing my skills to debug the errors, surely someone more experienced will have a better answer)
Hoping this helps you
Best regards