Ok, I'm not good at this but here goes:
1) the volume (101) has not been changed..so try to raise that 1st. Your volume might be too low. Probably not the answer, but let's start with the simple stuff 1st.
2) I see the midi meter up--which means the Sonar track is seeing midi, Omnisphere should have midi track one lit up--it looks like tracks1,2,3 might be lit in your pic. Is the "1" liting up?
3) In Omnisphere then there should be a horizontal meter movement indicating output. in your Picture there is no level in that meter. So it looks to me like something inside Omnispere is turned down.
4) You are in "Stacked" mode. Try getting out of that mode, go to the main page and with your mouse, load a new sound and push the button (Arrow) under the words "Power Synth". You should hear something without your midi channel involved.
I'm not sure I've solved anything, but maybe gave some clues, For what its worth, I use Omni all the time (and love it)