dock indicator light not working

Same issue. MBP Retina. Mountain Lion. Also, some open applications (like Quicktime) do not appear in dock even though they are running.

I too have the same issue since updating to Mountain Lion on my 24 inch mid 2007 iMac.

The only thing I do to reset the dock without rebooting is to Quit Process "Dock" in Activity Monitor and the Dock restarts itself and the problem "temporarily" is resolved until the next time.

I also have a 15 inch Early 2008 MacBook Pro running Mountain Lion and this phenomenon doesn't appear to affecting it at this time.

This cannot be a small number of users experiencing this problem.

😟

I wonder if I'm having the same issue or not. I see indicator lights for the finder and iTunes, but not for other running programs including Mail and Safari. Also not shown intermittently is the unread mail flag. When I turn indicator lights on and off, the Finder and Mail lights go off and on again, but no sign of life from the others.

I have Mid 2010 12.5" iMac, 10.8.1. I don't use rotating background photos, just a stock photo. My dock is located on the left.

Same here. Reboot always corrects it; other solutions are variably effective.

Well, I have same problem on the new retina macbook pro.

Also, I have noticed that after coming back from sleep it not only loses the indicator lights on the dock, if you were to right click on those apps you will not get the proper menu of when an app is actually running. Instead I get the menu as if the app is closed. So I dont get the quit option for example. Do you all get that too?

Yes - I hadn't noticed that but it's true for me too.

I notice that the indicator light for Safari and Mail don't show, but the ones for Finder and iTunes do. I had theorized that this happens after switching users and then switching back, but it could just be after sleeping - hard to say how to narrow that down.

In case it is the example I mentioned you need to start the "Activity Monitor" app. Within that app search for "Dock". On you find Dock, quit it. Dock will immediately restart on its own and all the lights will temporarily work again. This is not a solution to the underlying problem but does get the dock and the indicator lights working properly again temporarily.

Interesting. Ever since I installed ML, I notice that the light indicator for open apps and Finder are lower. For me, they sit on the edge of the dock, in front of the app. But they have always been there.

Same problem: MBA 2012 with Mountain Lion. Two other factors: I like to switch from app to app using Command-Tab. If the indicator light is off on the dock, then the App does not appear on the Command-Tab list. Although I have Power Nap enabled, I don't think it works. For example, I thought it was supposed to check mail when sleeping--but no new mail appears until after waking up.

I have exactly the same problems on a brand new MBP Retina:

1. Lights not appearing in the dock even if the applications are active.

2. Lights still appearing in the dock after the application has been closed.

3. Running applications not appearing in the Command-Tab list (related directly to point 1).

BTW, speaking of point 3., the reverse does not occur. i.e. application is closed and light still appears in the dock... BUT, the application is correctly missing from the Command-Tab list.

This problem is WIDESPREAD. It has nothing to do with the hardware you are running. It is a bug in Mountain Lion (most likely related to the sleep and/or power nap functionality). Apple has to fix it. Meantime we have to just be patient... and put up with the frustrating user experience.

This problem went away when I uploaded 10.8.2 (OSX).

I had this problem, and I was able to make it go away by trashing the dock plist file. It resets your dock to default so you have to put your stuff back in, but so far, it hasn't happened again. I believe I did this before 10.8.2, so I don't know if 10.8.2 fixes it or not.

4Years later still an issue. This seems a good fix anyway.