Subj01 --trglabel Subj01/label/ROI.label --hemi lh --regmethod 
surfaceandmris_anatomical_stats -l Subj01/label/ROI.label -b Subj01

I have run 

mris_anatomical_stats -l Subj01/ROI_neg.label -b Subj01 lh 

the following error has been produced:

Subj01/mri/wm.mgz...reading input surface Subj01/surf/lh.white...Using TH3 
vertex volume calcTotal face volume 211969Total vertex volume 209028 
(mask=0)reading input pial surface Subj01/surf/lh.pial...reading input white 
surface Subj01/surf/lh.white...No such file or directorymris_anatomical_stats: 
could not open label file Subj01/label/ROI_neg.labelNo such file or 
directorySubj01: could not read label file Subj01/label/ROI_neg.label

This error did not occur for another label (Red_positive.label) which is threshold over positive value.

Please take in account that the Blue_negative.label is obtain from FS-FAST map using tksurfer.

Blue_negative.label expresses the difference for FC of group B < FC of group A.
Conversely, Red_positive cluster shows difference for FC of group A > FC of group B

Please also note that clusters were thresholded before to save the .label with tksurfer +at 1.3 for defining Red_positive.label and at for defining - 1.3. I do not know if this step could induce an error in label properties.

Thanks

Stefano