Whenever I choose weighted FWHM for image rejection in the stacking tab, the stacking fails. When I choose normal FWHM then stacking works.
Are you sure you tried on the same sequence? The error indicates one image could not be read, I don’t see why it would not happen in both tries.
I wonder if some images were moved, or added to the sequence, or if the seq file is inconsistent with the FITS files for some reason.
No, I didn’t move anything. I have a feeling I’m getting many error messages since I switched to a SSD, Kingston XS2000.