@Soroosh 

I think SOLVER_LINKED_SOLVER_REMOVE should probably be called before SOLVER_DYNAMIC_LINEARITY_TYPE_SET if necessary- it seems a bit dangerous to assume we want to remove linked linear solvers any time  is called. I don't mind changing this but is there a reason this is set up this way? I'm guessing this was just a fix for an issue you found during PROBLEM_SETUP_START_ACTION for 1D coupled problems?

Cheers,
D