Comment # 1 on bug 918387 from Johannes Meixner

I can reproduce it but I cannot debug it.

Even "hp-toolbox -ldebug" and also "journalctl -r"
and even also "hp-check -t" do not show
any bit more information except the poor
"warning: CUPSEXT could not be loaded. Please check HPLIP installation."

I cannot debug issues in HPLIP without more useful information.

We (i.e. openSUSE) distribute HP's HPLIP software
but we do not develop it.

In case of issues with HPLIP please report them directly to HP via
http://hplipopensource.com/hplip-web/support.html

Preferably post an URL to your upstream issue report here
as reference.