3D electrocoalescence with multiple inlets

Hi I have based my simulation on the electrocoalescence example except I have two phases coming in at the inlet. As such I have defined an explicit boundary selection for each inlet phase and have two separate inlet boundary conditions for each phase. The velocity of each phase is the same but the Vf edit field is different in each case. I have tried different combinations of 1, -1 and 0 and none of them seem to work. I am getting the error

failed to evaluate variable jacobian tpf.Vf2 in domain 1 and I think my inlet boundary conditions may be the source of this problem.

Any help would be greatly appreciated. I have attached a copy of my mph file.