Simulation of leakage flux from transformer

Hello.

I've tried to simulate a quantity of leakage flux from transformer by using COMSOL 4.3a. To do this, I made a simple transformer model with LiveLink for AutoCAD.(I want to attach mph file, but its size is too big to attach)
And I chose "mef" module for simulation. But an error message comes out. Here is the message.

The following feature has encountered a problem:

Failed to find a solution.
Divergence of the linear iterations.
Returned solution is not converged.
- Feature: Stationary Solver 1 (sol1/s1)
- Error: Failed to find a solution.

I'm a beginner of COMSOL, so I can't find any solutions to fix this error. Is there any way to fix this error?

Regards,

Mizuki