I am trying to build an average subject (dataset with 38 subjects) under FS v4.0.5 (freesurfer-Linux-rh9-stable-pub-v4.0.5-full.tar.gz).  It seems to work fine. But, when I click the Analyze button of Qdec, the error show as below:

Writing to /usr/local/freesurfer/subjects/qdec/Untitled/contrasts.sig.mgh
reading group avg surface area 828 cm^2 from file
Reading in average area /usr/local/freesurfer/subjects/fsaverage/surf/rh.white.avg.area.mgh
reading group avg surface area 990 cm^2 from file
Reading in average area /usr/local/freesurfer/subjects/fsaverage/surf/rh.pial.avg.area.mgh
reading group avg surface area 828 cm^2 from file
Couldn't find file /usr/local/freesurfer/subjects/fsaverage/surf/rh.curv

I don't know how to deal with this problem. Could you tell me how to resolve this?

Thanks in advance.

Antonio