Hi Robert,
You maybe getting this error due to different version of MATLAB.
Check this page for reference: https://in.mathworks.com/help/matlab/ref/fitsread.html
Or try this:
% Obtain information about the FITS file
info = fitsinfo(fnami2);
% Get the primary HDU (Header Data Unit) index
primaryHDU = info.PrimaryData.Key;
% Open the FITS file
fitsFile = fits.openFile(fnami2);
% Read the image data from the primary HDU as raw digital numbers
imageData = fits.readImg(fitsFile, primaryHDU);
% Close the FITS file
fits.closeFile(fitsFile);
% Assign the data to the variable KAF
KAF = imageData;
