I have a very basic question regarding the usage of qdec.

I am using qdec to view cortical thickness for a set of patients vs. controls. I am able to create table.dat, design the comparison and display the results. After that, my results are saved as sig.mgh in qdec folder. Now when I try to reopen the same results by loading surface and overlaying with sig.mgh, although it shows me the results but when I click on 'Find Clusters and go to max' it gives me following error:

Error generating cluster stats GeneratingClusterStats: white surface was not found

 

and it doesn't display any cluster results in terminal window. If I do everything from very first step, starting from loading table.dat, creating design once again, everything is working fine.

I would really appreciate any help.

Thanks,

Sahil