If your iMac or MacBook pro etc get stuck on boot mode and your Mac doesn't start up, this will fix it. Re start your Mac on recovery mode by holding down "COMMAND + R " at the same time when you restart your Mac. Follow instructions on the video. It will take up to an hour for your computer to get fixed. Please let me know on the comment section of this worked for you, try it at your own risk, I'm not responsible if this damages your Mac.., like and share my video! Please subscribe !!! Thank you!