I ran both SAS and TASSEL on the same data and got results from SAS but TASSEL did not output an answer. Why?
While both SAS and TASSEL have criteria for convergence and maximum number of iteration, these may not necessarily be the same for each software package. In fact, they may define differently. This explains why you may get converged data from one but not the other. If you are curious enough, you may want to try changing the criteria and the maximum number in SAS. Most likely, you will get different results due to the changes.