I attempted to revert my software back to macOS Catalina by downloading the software from the appstore but was treated with this message: "This copy of the macOS Catalina installer application is too old to be opened on this version of macOS." Any helpful suggestions?
MacBook Air 13″, macOS 11.0
Hey all,
To preface, and as noted by other commenters, ALWAYS create a time machine backup with your pre-upgrade system setting, software, and files. Save yourself a lot of hassle.
In lieu of not backing up my previous OS via Time Machine, I was able to reinstall OS X Catalina using Internet Recovery Mode (Option + Command + R). Since I have the newest chip in my MacBook, the process wouldn't allow me erase my SSD drive before reinstalling OS X Catalina. As a workaround, I performed the following process: First, I booted in Recovery Mode (Command + R) and erased my SSD drive in the Disk Utility. Follow these directions in order to do this. Second, I rebooted in Internet Recovery Mode (mentioned supra). Third, I erased the SSD drive there too using the method in the link. Once that was completed, I quit the disk utility and then clicked Reinstall macOS. Worked like a charm. Reinstalling OS X from the basic Recovery Mode (Command +R) will not work because the reinstallation of macOS is for Big Sur––though it's the only way to first erase the SSD drive. After, Rebooting in Internet Recovery Mode (Option + Command + R) will allow you to reinstall Catalina. Disclaimer: On older generation MacBooks you may be able to simply use Internet Recovery Mode to erase and reinstall OS X.
Note: I didn't need to install Catalina on a flash drive or create a bootable installer.
Hey all,
To preface, and as noted by other commenters, ALWAYS create a time machine backup with your pre-upgrade system setting, software, and files. Save yourself a lot of hassle.
In lieu of not backing up my previous OS via Time Machine, I was able to reinstall OS X Catalina using Internet Recovery Mode (Option + Command + R). Since I have the newest chip in my MacBook, the process wouldn't allow me erase my SSD drive before reinstalling OS X Catalina. As a workaround, I performed the following process: First, I booted in Recovery Mode (Command + R) and erased my SSD drive in the Disk Utility. Follow these directions in order to do this. Second, I rebooted in Internet Recovery Mode (mentioned supra). Third, I erased the SSD drive there too using the method in the link. Once that was completed, I quit the disk utility and then clicked Reinstall macOS. Worked like a charm. Reinstalling OS X from the basic Recovery Mode (Command +R) will not work because the reinstallation of macOS is for Big Sur––though it's the only way to first erase the SSD drive. After, Rebooting in Internet Recovery Mode (Option + Command + R) will allow you to reinstall Catalina. Disclaimer: On older generation MacBooks you may be able to simply use Internet Recovery Mode to erase and reinstall OS X.
Note: I didn't need to install Catalina on a flash drive or create a bootable installer.
You can't run an installer for an older macOS version than you're running. You would need to erase the drive and restore from a backup.
Sorry you are having this problem. Also, for what it is worth, it's important to know that iCloud is technically not a back up system. Various activities can and do change or delete iCloud files, so it isn't "fixed" as a true back up is. I hope this makes sense. What we recommend you do (later when this is resolved) is to get an external drive to use for back up. Time Machine is designed to do that for you. The external drive doesn't have to be a higher cost SSD, but should be two or three times larger than the data being backed up. I hope all works out for you.
Thanks—but I don’t have a time machine backup. I have all my files saved to the cloud. Is there a way to downgrade without using a time machine backup?
Advice for the future. Never, ever, install beta software on your working machine. You will almost always come to regret it as you are now.
You're welcome. FWIW, the very first thing you should always do before installing a beta version of macOS or just an upgrade is to create a Time Machine or other backup.
That being said, you will have to create a Catalina USB Bootable installer onto a flash drive, boot from it, then erase your drive and install Catalina. Anything that is not backed up to iCloud will be lost such as any software you have installed.
How to create a bootable installer for macOS - Apple Support
Reverting back to macOS Catalina from Big Sur
