The Spotlight search tray will magically become available again.Select your native resolution again, changing your screen resolution back to normal.Click ‘Displays’ and select a resolution smaller than what you are currently using, 640×480 seems to always work.Open “System Preferences” via the Apple Menu.This is a strange fix but it works everytime for me when my Spotlight menu icon highlights but the search form doesn’t appear.Note: You can also rebuild the Spotlight index with MainMenu, mentioned in Solution #4.Wait until index is finished rebuilding, this can take a while depending on the size of your hard drive, amount of files, etc.
You will receive a confirmation message saying that index will be rebuilt.You will be asked for your password, provide it, as this command requires administrator privelages to run.At the command prompt, type this exactly: sudo mdutil -E /.Launch ‘Terminal’ (located in /Applications/Utilities/).Solution #2: Rebuild the Spotlight Index manually Within a few seconds the menubar will rebuild itself and often Spotlight will magically work.Locate the process ‘SystemUIServer’, highlight it, and click the red button “Quit Process”.Launch ‘Activity Monitor’ (located in /Applications/Utilities/).While not entirely sure what causes any of these problems, try these troubleshooting methods that frequently work to repair Spotlight: The Solutions: Troubleshooting Spotlight