MacOSX 10.8.2: How to clear unwanted power-management assertions?

Question

There are some programs that run under MacOSX Mountain Lion which are now (since installing 10.8.2) causing unwanted power-management assertions to be set. I'm looking for a way to clear assertions like these.

Here's one example: one or more of these programs cause the following power-management assertion to be set within "powerd". Note the "powerd" line, below ...

% pmset -g assertions    
10/7/12 11:51:47 AM EDT  
Assertion status system-wide:
   PreventUserIdleDisplaySleep    1
   CPUBoundAssertion              0
   PreventSystemSleep             0
   PreventUserIdleSystemSleep     0
   ExternalMedia                  0
   UserIsActive                   0
   ApplePushServiceTask           0
   BackgroundTask                 0

Listed by owning process:
  pid 18(powerd): [0x00000005000001d7] 11:24:18 PreventUserIdleDisplaySleep named: "com.apple.powermanagement.delayDisplayOff" 
... etc. ...

These programs exit and leave this power-management assertion in place within "powerd", and it remains active forever. This prevents "display sleep" and the screen saver from ever being invoked.

The only option I know of in this case (aside from rebooting) is to do a "kill -HUP" on the "powerd" process. This causes that daemon to exit and restart without the incorrect assertion.

Does anyone know of a way under 10.8.2 for me to clear the "PreventUserIdleDisplaySleep" assertion within "powerd", without forcing a restart of that daemon? I'm happy to do this via a Cocoa, Carbon, or AppleScript program, if necessary.

I know about IOPMLib, but the routines within that library only seem to be able to clear power assertions that have been created within the same process. I need a way to tell the external and already-running "powerd" process to clear the "PreventUserIdleDisplaySleep" assertion that it manages. Does anyone know of an API for externally setting and clearing power-management assertions within a running "powerd" instance? Perhaps via some sort of notification ... ???

Answer 1

The answer is very simple. I had the same problem.

Make a back up of the following folders that can be found in /Library/LaunchAgents/LaunchDaemons/Internet Plug-ins. Next. Empty the contents of the folders. Then restart your mac. Test your energy settings or just test in terminal (pmset -g assertions). Your problem should be solved. You can put the files back one by one to find the file that's causing the problem or leave it this way.

You'll get a pop up when you use Safari and there are missing plugins. You can simply reinstall them. Your mac should work fine either way.