Hello FreeSurfer Developers,

I'm attempting to compare two groups' cortex, but for some of my subjects I get the following error when I run mri_glmfit \
  --y rh.thickness.10.mgz \
  --fsgd g3v1.fsgd dods\
  --C group.mtx \
  --surf fsaverage rh \
  --cortex \
  --glmdir g3v1.rh

 ERROR: DOF=0(this is error?)   g3v1h.rh only 4 files(should have beta.mgh sig.mgz files...)

I've searched the list and no similar errors have been reported. 
1) FreeSurfer version: freesurfer-Linux-centos6_x86_64-stable-pub-v6.0.0-2beb96c
2) Platform: ubuntu 16.04.6 LTS 
3) mri_glmfit.log  and  figure01 figure02 figure03: see attached