Joule Heating- 3D Rectangular Bar

I have 3D model of a rectangular Copper bar with 3 rods attached to it. These 3 rods provide electric energy to heat the rod. I am not sure what is incorrect with the case set-up, asI have run a very similar case set-up in a different modeling code, and I get the error 'Unable to solve for T'. Ideally I would like to include Real and Imaginary components of Amps (as a current density input).
Any suggestions will be appreciated. Thanks!