In the tutorial you mention is not clear to me what are the steps for the whole process. May be it is in different tutorials so let me clarify what I do to check if there is some mistake.
I combine aseg with cortex and obtain a whole brain(without dba or source of any type, it is not clear here if I have to add something with volume how??). Then I compute headmodel, covariance matrix and source for mri volume option. Here I see I think is where we add volume scouts from atlas. I can do that but I already have a source model where almost there is activation for each time in the whole brain. May be I did something wrong.
About fsaverage I didn't meant to use it as template but I use parcellations from those files in fsaverage. If not where from I can obtain aseg+aparc files? From a segmentation with recon-all that is computing freesurfer over IBCM152 template. Where can I find this template then? To my knowledge I can download from a link of McGill but it doesn't seem to work. May be it is dowloaded in another software as well where I can get it easily.
Also I want to mention that when I use ay atlas from spm to scouts I ony see numbers and not the names of those scouts. Is there something I am missing?