Where are all my tray icons??? >:( Btw.: there is only one single reboot were two reboots inbetween the two views!!!
Try a second reboot. One thing I noticed, even going back to the betas/RCs was that often a second reboot solved the problems (not ideal I know).
How come 2-3 reboots are now required when in previous versions one was sufficient.?
I don’t know, hopefully the Avast! team will sort it soon. 
Even a third or fourth reboot did not bring back the icons. Btw: the avast-icon itself appears only after having started avast-user-interface …
Btw.: UNINSTALLING AVAST brings back the icons (all of them)!!!
Same problem on another PC with avast v9: where have the tray-icons gone???
As uninstalling AVAST brings back ALL the icons, the problem is clearly avast (and nothing else!)