Have a weird problem with one of my project files. I went into the metronome properties to increase the dB output and after saving those settings the metronome no longer works. I checked other projects and it's working fine. I also triple-checked to make sure the Metronome was outputting to the correct bus and that all the other routing was correct. And it's not muted either nor is any track soloed. I'm at a loss and don't know how to get it back!

If it is working on other projects, it must be routing... or maybe some inadvertent automation change of gain or volume on the submix buss... I've run into this in tracks that suddenly stop working or stop for awhile... usually was an intial automation level of zero.  A few times over the many years metronome has disappeared and it was always buss routings that I discovered after scratching my head in frustration for awhile.
 
maybe try inserting another buss and reassigning it to that, which routes to the master...

Vastman
If it is working on other projects, it must be routing... or maybe some inadvertent automation change of gain or volume on the submix buss... I've run into this in tracks that suddenly stop working or stop for awhile... usually was an intial automation level of zero.  A few times over the many years metronome has disappeared and it was always buss routings that I discovered after scratching my head in frustration for awhile.
 
maybe try inserting another buss and reassigning it to that, which routes to the master...

Ah, had the bypass all audio effects setting turned on for some reason. Duh!