While rare, you might experience a problem in OS X where the Finder will not display the contents of specific folders. When this happens, you can usually browse other folders and open files and applications, but when you try to load the affected folders, the Finder will just sit with an empty window and display a revolving indicator at the lower-right corner (note that this is no the notorious spinning color wheel that commonly indicates hangs and other problems in OS X).

When this happens, you may also notice notably lower battery lifetimes, as well as high CPU usage indicated by a hot computer chassis as well as blaring fans, though these might hot happen for a few minutes after the problem begins. Even though these behaviors suggest a problem with your Mac, various other programs you are running may not show any slowdowns or problems at all. This is because this specific issue is occurring from a fault in the system’s Spotlight index-handling routines that is affecting the Finder.

To fix this problem, you will need to open either Activity Monitor or the Terminal utility, so if you have either in your Dock then you should be able to open them from there. Alternatively, you can attempt to use LaunchPad to search for and open either of these.

If you can open Activity Monitor directly then perform the following steps:

1. Choose “All Processes” from the View menu
2. Select the “CPU” tab
3. Click the “%CPU” column in the list of processes

At this point, you should see the process at the top of the list that is the cause for the issue at hand. This will likely be called “mds,” so select this and use the toolbar option to quit the process. At this point the high CPU usage should stop, and the problematic Finder folders should now display contents, without the need to restart or log out of your system.

No Access to Activity Monitor?

If your Applications or Utilities folders are hanging, then you may be out of luck and will have to force-restart your system; however, there are a few approaches you can take before resorting to this. First, try using Apple’s LaunchPad to open Activity Monitor, as this will bypass the need for using the Finder to access the program.

Alternatively, if you have access to the Terminal, then you can try using it to launch Activity monitor by running the following command:

open -a "Activity Monitor"

If this is successful, then you can proceed with Activity Monitor for quitting the “mds” process. However, if Activity Monitor still will not open, then you can run the following command to force the mds process to quit (supply your password when prompted–it will not show when typed):

sudo killall mds

Keep in mind the system will continually attempt to re-index your system, so expect this process to start back up again (perhaps immediately); however, it should only use about 20-30% of your processor on average, and should end after a short while of running.

Finally, if you neither have access to the Terminal or Activity Monitor, then you can likely fix this issue by going to the Spotlight System Preferences, then to the Privacy tab, and click the plus button. In the drop-down panel, press Shift-Command-C and then select your hard drive to add to the privacy list. Confirm you wish to do so, and then remove the drive from this list after a few seconds. This will trigger a rebuild of your Spotlight index, which should have the “mds” process work properly, though this is not the preferred approach as it will now take a while for the index to be rebuilt, which may take hours and have several “mds” processes cranking in the background.

Other Possibilities

Even though this behavior is likely caused by faults with Spotlight’s metadata indexing, it can be caused by other issues as well. These include faults with the Finder, in which case you can either log out and then back into your account (or restart) to refresh the Finder, or you can use the system’s Force-Quit window (press Option-Command-Escape) to select and force the Finder to quit.

Secondly, if your hard drive is experiencing formatting problems then this may affect the system’s ability to display folder contents. This can also caused tiered effects as it may hinder indexing as well as lower-level system services like virtual memory management (and lead to more severe hangs and crashes). To fix this, first be sure you have a full backup of your system, and then reboot your Mac into Recovery mode and use Disk Utility to verify and repair your Mac’s hard drive.