Sorry, I think I figured the issue out based on the previous conversations. Just for the record, I sourced freesurfer 5.3 and resaved orig.mgz for this subject using the following command:

mri_convert mri.orig mri.orig

Apparently it corrected the problem.

Regards

From: freesurfer-bounces@nmr.mgh.harvard.edu <freesurfer-bounces@nmr.mgh.harvard.edu> on behalf of Nasr, Shahin,Ph.D. <shahin.nasr@mgh.harvard.edu>
Sent: Wednesday, July 22, 2020 12:44 PM
To: freesurfer@nmr.mgh.harvard.edu <freesurfer@nmr.mgh.harvard.edu>
Subject: [Freesurfer] tksurfer - failed to calloc

Hi Surfers,

I get the following error when I use tksurfer for one of our subjects:

znzTAGskip: tag=1830834290, failed to calloc 1834378240 bytes!

To clarify, this error is only limited to freesurfer version 6.0 and 7. But version 5.3 works fine with the same subject.

Regards