gscan2pdf does not work with HP Officejet Pro 6830 via Network

[Josy]

sudo apt-get install hplip hplip-gui

hp-setup

search for network scanner (in my case connected via WLAN)

When the scanner is found, select it.

start e.g. from commandline:

gscan2pdf --log=log

The program starts up and then wait for some time.

A gray box without content appears. See screenshot.

After running hp-doctor and hp-check when starting gscan2pdf, the same error message appears, like with USB Bug #1500500.

 Furthermore after passoword entry hp-doctor complains, that it can not start the package manager, as it is already open. Which was actually not the case.

[Josy (josy1)]

Note:
- HP Deskjet 930C (as found in the log) was not attached

HP Officejet Pro 6830 connected via WLAN as descibed above.

[Josy (josy1)]

The file ~/.gscan2pdf is attached.

[Josy (josy1)]

The screenshot described above is attached.

[Josy (josy1)]

Here the output of:
hp-check -r -t