Yeah, friction is a real pain. I generally run the model and look at which nodes are not converging and then remove friction from those nodes specifically. That generally lets me get a conversion eventually. Once I have updated the model with any needed changes I go back and put the friction back in and try and get it to work. Sometimes I get lucky, and other times I don't.

One thing I have started doing is running both a standard operating case without friction and then a standard operating case with fricition using the controls in the load case editor to change that between run.

Thanks,
Duncan