Hi Rick and Paul,

Thank you both for trying and replicating the command!

So adding the complete name (NAME.nii, NAME.nii.gz, NAME+orig, NAME+orig.HEAD) was still giving the error, and running the brew install netpbm didn't install the package for some reason, same thing with updating the binaries.
The command:
# /bin/bash -c "$(curl -fsSL [raw.githubusercontent.com];
returns: undefined variable error

Will try the afni_system_check.py -check_all next. But update, the -jpg function works and produces an output! Thank you for the suggestion, will replace -png with -jpg in the script moving forward.

Your help is much appreciated!

Best,
RJ