Hi Loner T, I have read you solution to downgrade to Catalina, Install Windows 10 and upgrade to Big Sur. I couldn't find any trustworthy ways of doing so.
Please provide the steps of how to downgrade from Big Sur to Catalina.
MacBook Pro 16″, macOS 11.4
If your Mac originally was built with Big Sur installed you can not downgrade.
Why don't you explain what your issue is rather than determining that you have to downgrade, install Windows, then upgrade?
I use a MacBook Pro 16" which came with Catalina. I installed Windows 10 with bootcamp and later, upgraded to Big Sur. I had some driver issues and I had to remove the bootcamp partition. Now, I'm unable to reinstall Windows 10 as bootcamp gives me a disk partition error. Time Machine/File Vault were turned off and local Time Machine snapshots were removed but still gave the same error. Manual partition using disk utility also fails (also tried it in Recovery mode) but a terminal way of partitioning to FAT32 instead of APFS was successful.
Further online forums claimed APFS and Big Sur were buggy and then I landed on a similar question on apple discussions which was answered by Loner T and concluded that a downgrade to Catalina, bootcamp installation and an upgrade back to Big Sur solved the issue but no info was given on how to downgrade. So, I had to ask here again addressing Loner T which is answered now.
Sorry for the trouble. The question was for Loner T. Thank you for responding BobTheFisherman!
It is good that Loner T responded and that the response solved your issue. I was trying to get to the root of your issue. There should be no reason for you to have to downgrade to install Windows. But if you are happy with the downgrade solution I guess that is the end of it. All the best.
One more thing, addressing posts to individual users here is not very efficient. This is an open community and anyone can respond to any post.
Usually, there are two areas in Big Sur which cause problems. EFI and APFS.
APFS issues can be corrected in some cases with fsck_apfs, but may require a erase/restore if fsck_apfs cannot correct them.
EFI issues get more tricky, and result in black screens and GPU drivers misbehaving. Bootcamp installation can also fail because the EFI partition cannot be updated.
If after the downgrade/upgrade, you still see issues, please post back.
Must have been an EFI issue for me.
A few days after the Big Sur update, I got some minor Windows updates, after which the AMD drivers disappeared. Tried installing several times after multiple restarts from the official AMD site but the wizard always said 'no AMD hardware detected'. So, I finally removed the partition and couldn't reinstall it due to the same disk partition error.
Will update after the downgrade/upgrade.
[Loner T] How do I downgrade?
