Seems I get a failure when I try to stack images using the SSWEIGHT keyword.
*** Error: /Volumes/Public/m33_subs/lights_calibrated/CC/approved/registered/Redm33_luminance_520s-6_178E.00002_c_cc_a_r.xisf: Nonexistent or invalid weight keyword 'SSWEIGHT'.
<* failed *
I open the image and look at the fit header and clearly the information is there.
Am I missing something?