When I run recon-all i get the follwing error message:

 mri_watershed Error: 

 GLOBAL region of the brain empty !

Linux 02f92500bcfb 4.15.0-36-generic #39~16.04.1-Ubuntu SMP Tue Sep 25 08:59:23 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

recon-all -s sub-XYZ exited with ERRORS at Thu Oct 11 15:10:22 UTC 2018

The .nii file looks fine. Can someone help me with this? 

Best,

Boris