cpl42 Error: PCL Legacy FITS Format Support: Unable to open FITS file: {file path and name}
What precisely is the path and filename string (the part you left out)? That could tell all the story (whether it is a path name error, or whether it is a FITS header error.
Try make a copy of one of your images, and rename it to something simple like "test.fits". See if that works.
If it does, there is something wrong with the file name. Could be the path is too long, or it contains some off character (Greek character, or odd punctioation character that you have named the target (ASAIIR does not check for the legitimacy of the target string when used as part of a file name), etc).
Chen