Problem with non-parametric cluster-level statistics (permutation tests)

Hi Alfonso,
I am running a surface-based functional connectivity analysis with conn and it is going well until the permutation tests for second level analysis. It always froze on the interface "updating non-parametric statistics, please wait" and could not proceed and got the results. I have tried used another version of conn as well as another computer, but i still cannot solve this problem. Do you know why and how could I get the results of non-parametric cluster-level statistics? 
Thanks,
Huan