revert

I have had some random problems with Big Sur since 11.3 (ex. photo screensaver doesn't work anymore, much slower & the 'beach ball' is showing up all the time, etc.) I assume anything that I have added to my Mac since then will be gone? I have a Time Machine backup but wasn't sure if I could...

Is there a way to batch revert all the photos in my Photos library to their original states? I’m guessing it’s a no for mobile devices, but what about Photos on Mac?

Before I upgraded to Big Sur I backed up Catalina System settings in Time Machine. Is it possible to revert to Catalina OS or will I make everything worse? I have not made any backups in that drive since installing Big Sur. Just really want to get rid of this shi*ty OS.

I have a 2013 Retina 13 running High Sierra. Yesterday I upgraded to Safari 12.1. The description sounded like a minor update, so I just went ahead and did it. It has ruined Safari. Safari is now crashing constantly without any warning, multiple times per hour. I'm very lucky if I can get 15...

Since upgrading to High Sierra, whenever I update a note in Notes, it will always delete my entry and revert back to what it was before my update. Only after I enter data a SECOND TIME does it "stick." Anybody else seen this bug?

Not looking for debate about whether iOS 11 is great or not. I would just like to revert to iOS 10, if possible. Is there a way to downgrade to iOS 10 from the official iOS 11 release? If so, how can it be done?