I also have the same issue, as others have reported before. I have tried several Matlab version (from 2014 to 2022), and different operating systems (MacOS and Windows) and the error persists. The only way I get to prevent the never end loop is running twice the estimation GLM parameter. However, the result I get after calculating the activation p values is a blank surface of the rendered brain, without any significant cortical activation value. Looking at the beta values, it seems that they are smaller than they should be, or at least when you multiply them by 5 or 10, for example, it results in a cortical activation figure closer to that represented in the manual, but still not the same. 

I wonder if someone found a solution to this issue. Any help would be much appreciated.

Best wishes,

Manuel