When this happens, it may appear that no application will reactivate. Apps may continue to function in the background, but as Expose is stuck and covering the whole screen, it will prevent you from using the mouse to interact with any of the open apps. If this happens or has ever happened to you, you might think that forcing the system to restart is the only option. But if you have important work open and don’t want to disturb your workflow, there is another relatively easy way to solve the problem.
What you should know, is that Mission Control is actually commanded by the Dock in OS X. Any issue with the Mission Control can easily be solved by simply force-quitting the Dock. And since the Dock is a persistent service in OS X, it will automatically re-launch when you force-quit. To do this, you’ll need to enter a command in Terminal, but as Expose will prevent you from using the mouse, you’ll need to use your keyboard to open it. To do this, simply follow the steps below:
Open Spotlight by pressing “Command + S” on your Mac keyboard.
Enter the word “Terminal“. Terminal should appear in the search, simply press Enter to open it up.
Simply run the following command in Terminal, and press Enter.
Once done, the stuck Expose view should disappear, and the Dock should then reappear on your display. Your system will now be up and running again. Be sure to clear any confusion or ask any questions in the comments below.