Please use DS9 version 7.5 with IRAF
William Joye wrote on Jul 03, 2018
It has come to our attention there are a number of issues with DS9 version 7.6 and IRAF. These issues have been addressed and a new version of DS9 will be available with the release of our next beta version, 8.0b1.
We recommend the use version 7.5 available here:
http://ds9.si.edu/archive/
until the time of the next beta release.
Last post on Jul 03, 2018