I drawed a 3D ROI on the original image using freeview,and saved it as an label file. Then I wanted to sample it to my subject and to found the closest surface vertices so that I can extract the cortical thickness of ROI. I used the command line: mri_label2label --srclabel 4gt.label --s PT1_4 --trglabel 4reg.on-pial.label --hemi rh --paint 30 pial --trgsurf pial. But it reported error: Line 3:4445 Segmentation fault(core dumped), mri_label2label.bin "$@".