Downgrading from Big Sur Beta to Catalina

[decisions]

Hey all,

My 2018 MBP is my first Macintosh, and so I am inexperienced regarding Time Machine/OS downgrades on Mac and just had a a few questions.

I upgraded to the Big Sur beta but have decided to downgrade (Spotlight Search is broken, seem to have kernel panics more frequently). I didn't make a backup before I upgraded, but I did this knowing that anything I really needed was on iCloud already. My questions are

1. If I use Time Machine to back up to an external drive now, will I be able to restore whatever files are compatible once I get Catalina up and running again?

2. Is there any chance that my iCloud files (mainly documents) will be incompatible with Catalina for some reason?

Thanks.

 

[gilby101]

1. Probably/possibly no. There are significant/major changes to TM and APFS. These are undocumented, but in many circumstance is seems they are not backward compatible. I would not risk being able to read BS TM with Catalina.

Just copy important stuff to an HFS+ format drive before wiping the boot disk and reinstalling Catalina.

2. Unlikely. This year (unlike 12 months ago) Apple do not seem to be attempting to make major changes to iCloud.

 

[NewUsername]

I also downgraded, the only way that worked for me was to boot the Mac in recovery mode (cmd + R), reformat the drive, now boot in internet recovery (cmd + option + R), reformat again and then reinstall. I’m a noob in this though, but at least it worked.

 

[minifridge1138]

I also downgraded, the only way that worked for me was to boot the Mac in recovery mode (cmd + R), reformat the drive, now boot in internet recovery (cmd + option + R), reformat again and then reinstall. I’m a noob in this though, but at least it worked.

That's not really a downgrade - that's a "wipe the drive and start over". Unfortunately, that's not something Apple lets Macs (or iStuff) do.