Tvheadend

Check the following:

• You've assigned a network to an adapter.
• The adapter is enabled.
• You have muxes listed in Config -> DVB Input -> Muxes.

could you resolve your problem?
I just setup tvheadend 4.0.8 on ubuntu 15.04 and have the same problem:

Under config > DVB-inputs > TVadapters I have 3 adapters (adapter0-2)

Under config > DVB-inputs > networks I have a network for ASTRA 19.2E defined with
network discovery: yes, orbital position 19.2E, character set auto

Under config > DVB-inputs > TVadapters I assigned this network to each of the 3 adapters and set them to
universal LNB (I have a quad-LNB with 4 full channels, not a switch)
enable
initial scan: yes
idle scan: yes

Under config > DVB-inputs > Muxes I have one mux only (DVB-S but no DVB-S2), and this says:
scan status IDLE
scan result: FAIL # services: 0 # channels: 0

A forced scan under networks does not seem to do anything.

PS: just in case you wonder: The 4th channel of the quad-LNB goes to an ordinary settopbox receiver and there I can watch DVB-S2 channels perfectly.

OK, i found my reason: the kernel supplied drivers did not work for my card. They come included in openelec, but not in ubuntu. so I installed the LinuxTV.org drivers and now it works.
never mind.