Apple said that would run happily on a late 2009 or later MacBook or iMac, or a 2010 or later MacBook Air, MacBook Pro, Mac mini or Mac Pro. If you Mac is supported read: How to update to Big Sur. Dec 02, 2020 Install Mac OS X 10.11 El Capitan on an external drive. (Download El Capitan from Appleās site.) El Capitan seems to be the last release that can migrate files from Snow Leopard.
A Troubleshooting Procedure that may Fix Problems with macOS El Capitan or Later
You should try each, one at a time, then test to see if the problem is fixed before going on to the next.
Be sure to backup your files before proceeding if possible.
If none of the above helps then make an appointment at the Apple Genius Bar for service. If you need to find an Apple Store - Find a Store - Apple.
Ways to help make a slow Mac faster
Mar 24, 2018 12:30 PM