Do not know whether Mac users occasionally encounter the menu bar is "Frozen" to be unable to operate the situation appears, this time will appear a small colored ball in the menu bar hover. In many cases we can solve this problem by shutting down a single application that causes problems. But sometimes you may need to completely shut down and restart the menu bar to solve the problem.
Menu bar: More precisely in the menu bar on the right side of the screen, it is controlled by the systemuiserver process of OS X. As a result, the menu bar can be restarted simply by shutting down the systemuiserver. There is no option to reboot the menu bar, so we can use the following two methods to restart the menu bar.
Fast Shutdown and restart the menu bar tutorial in the Mac
Method One:
1. Open the Activity Monitor.
2. Click on the Memory tab and search for Systemuiserver in the search bar on the right.
3. Select Systemuiserver, then click "X" in the upper-left corner and click Force Exit.
Method Two:
1. Open the terminal.
2. Enter Killall-kill Systemuiserver and press the keyboard to return.