I'm trying to get back to Catalina from Big Sur - there is plenty of info on the Net how this is done. However, I get a pop up telling me "This copy of Catalina installer is too old to be opened in this version of macOS." I m not too technical so I could be the problem!
OS
iMac 27″, macOS 11.1
That is because a Mac cannot install or boot from an OS version older than what it came with. So, if you had Catalina previously, it should be fine, but you need to completely erase your hard drive first and then you need the backup you made before upgrading to Big Sur. You simply boot into recovery, wipe your drive and then restore from your backup.
That is because a Mac cannot install or boot from an OS version older than what it came with. So, if you had Catalina previously, it should be fine, but you need to completely erase your hard drive first and then you need the backup you made before upgrading to Big Sur. You simply boot into recovery, wipe your drive and then restore from your backup.
It should; check though - I've read that CCC is now compatible with Big Sur (it wasn't for a while).
If you do have a clone, it is simpler to go back: boot into your clone (and, at that point, you will know immediately if it works (or not if it doesn't boot up). Then boot into recovery on your clone, erase your hard drive, make sure the format is still correct, and then simply clone back your Catalina system.
Thank you babowa for getting back to me on this. My iMac is a late 2015 model and I have upgraded OS software consistently since then. And last week upgraded from Catalina to Big Sur. I use CCC software to back up my internal HD to an external HD once a day. I did not make a specific backup of my internal HD prior to upgrading. Will the "CCC" backup work? Cheers, Peter
Thanks babowa. Let me see what I can do with this info. I'll let you know how it goes. Peter
Big Sur back to Catalina
