hplip GS can't open initial device

     I am sorry to have to reopen this, it was working long ago and now is not.

     running CPANEL with CENTOS 7.7.1908 (Core)

     GS 9.2.5

     HPLIP 3.15.9-5.el7 per yum list hplip

     Running testgs it bombs out with " can not open initial device."

     gs -sDEVICE=ijs -sIjsServer=hpijs -dIjsUseOutputFD
      -sDeviceManufacturer="HP" -sDeviceModel="Office Jet Pro 8600" -
      -sOutputFile=/tmp/data.out /tmp/data.print

     /tmp/data.print is a valid PS file produced by Gnuplot.

     Thanks in advance

     Homer W Smith
     Lightlink Internet