[Freesurfer] mghWrite error

Hello all, I have a few scans I need to convert using mri_convert but I receive this error:

writing to 2.mgh... mghWrite(2.mgh, -1): could not open file ERROR: failure writing 2.mgh

I can convert other images from the same scanner, same subject, same header without any problems but the few that I have recently tried to convert have this issue. I can view the images in tkmedit so I don't believe there is an issue with the images themselves. What does this error mean and how can I override it? Thank you all for your input, Thang Nguyen ------------------------ Thang Nguyen Biomedical Informatics Research Network Psychiatry and Human Behavior - Brain Imaging Center University of California, Irvine