Error in modeling time dependent objects.

Hi all,

I want to simulate the magnetic field which is around a wire with current, and surrounded by air. The problem is in 3D space and time dependent. I have used 'magnetic field' and 'external current density' options in Comsol.

I can get no result by running the simulation and the following error messages is shown.

failed to find consistent initial values. matrix has zero on diagonal. last time step is not converged. feature: time dependent solver1.