You have to improve the element shape where the solver is unable to obtain a force equilibrium and fails to converge.
You can find out where that is by typing a 4 in the field called Newton-Raphson Residuals under the Solution Information Folder. Take out the NEQIT command. Solve. When if fails to converge, you will have 4 plots under the Solution Information folder. The plot is the Newton-Raphson Force Residual plot. The Maximum value on this plot is where you need better elements.
I already know that it will be in the interior corner. If you put a small radius in that corner instead of a sharp interior corner, that will help it converge.