This is making me crazy.  I have one project where the metronome has disappeared and I can't figure out why.  The metronome is present on other old projects and on new ones that I have begun after the problem project.  It's clear from the console view that no signal is reaching the Metronome Bus although that is the one I have selected for the Metronome in Preferences.  I have tried routing it to other buses as well and it doesn't show up anywhere.  I have re-initializing Sonar.  I'm at a loss for what to try next.
(I am using the 2017.5 version of Platinum.)
 
Any suggestions would be much appreciated.
 
thx
 
//p

The only suggestion I can think of is to choose some different sounds for the metronome and see if that changes anything. You could also try to use a midi note as the metronome just to experiment.

http://forum.cakewalk.com/weird-metronome-issue-in-platinum-m3560048.aspx
 
This link is to a recent topic concerning the metronome.  Turns out that if you have the global FX off in the control bar while you make changes to the metronome, the metronome goes silent.  Solution is to toggle FX back on in the control bar or hot key 'E.'  I think I got that right.  And I just checked, it is still occurring with Splat 2017.06
hope this helps!
 

Hi. I have heard of cases where bypassing (off / on) all audio fx (E) has cured this problem.
Might be worth a shot.
Or try to delete the old, and make a new metronome bus, if you have one.
All the best.

It was the global effects "feature"!!!  Thanks - I don't think I would ever have figured that our on my own.
 
//p