On some critical OS X Error, Keep your Mac, MacBook, iMac fresh by reinstall or Repair Mac OS X. So, You just need to update or Repair your OS X on Mac, Here you can try or follow the steps for OS X EI Capitan, Yosemite, Mavericks or Lion.
Apple gives official way to resolve error through the Erase and Repair process. Quite simple but you need some knowledge about Disk utilities on your Mac. if you made a partition for running different OS X or Windows OS on Mac, MacBook or iMac. Then be safe and work within your OS X that’s you want to erase and Reinstall fresh OS X with bug/ Error fixed.
Steps for reinstall or Repair Macos Mojave, Sierra, EI Capitan
Reset all factory settings by erasing your mac and then reinstall all in-built apps and tools, Settings.
Prerequisite: Before start reinstall or Repair Mac OS X, Keep all useful files and folder in external drives. Time of repair/ reinstall OS X, Power adapter must be connected and turn on.
Step 1: Go to the Apple Menu > Restart.
Step 2: Before start again, on gray screen press command and R key continuously.
Step 3: Next, Choose the disk utilities > Continue.
Step 4: Now, Go with your Startup disk and Click on erase option.
Step 5: Then, From the format menu, click on Mac OS Extended. Place the name and Erase drive.
Step 6: Once you erased, Disk Utility > Quit disk utility.
After that, you can install new OS X on your Mac.
Install New OS X – Mojave, Sierra, Capitan, Yosemite, Mavericks
in the process of reinstall you device connected with internet.
Go to the Apple Menu bar > Restart. you Mac will restart and Press Command + R.
Go with Reinstall OS X > Continue.
Follow the on screen OS X installation process, in which disk you want to install OS X.
Once setup is done you can new enjoy error free new OS X On Mac.
In reinstall or Repair Mac OS X Mojave, High Sierra, EI Capitan, Yosemite, you don’t need any external bootable DVD or USB like windows. Your Mac automatically extract OS X saved on drive.