I am analyzing a thin walled steel I-beam (formed by connecting two channel sections back to back). The analysis involves two steps- an elastic Buckling Analysis followed by a Non-Linear Static General Analysis. The Non-linear part incorporates the geometric as well as material non-linearity. When I perform the non-linear analysis, several Zero Pivot warnings appear before the analysis is aborted with the error message "Too many increments made for this Step".

I am attaching the .cae file for reference, if I was unclear with my words. Any help would be greatly appreciated.