A seemingly small number of Mac users are reporting that their machines have been bricked after upgrading to macOS Catalina.
It is believed a potentially unsuccessful EFI firmware update is responsible for the issue. All affected users see nothing but a folder icon when attempting to boot up their Mac.
Most of the problems are small but frustrating, and should be fixed relatively easily with future updates. But there’s one that has left a small number of Catalina users with no Mac at all.
Catalina leaves some Macs unusable
“I’ve just ‘upgraded’ to Catalina,” writes one person on Apple’s official support forum. “My laptop is now bricked. All I get is the ‘folder?’ logo or nothing at all.”
“Me too,” writes another. “Same exact issue. It seems the update must have corrupted the firmware on the logic board since it no longer recognizes key combos.”
It’s not completely clear what is causing this problem, but it does sound like a corruption issue of some kind. That is typically what causes a Mac to display the folder icon when booting up.
Some users believe it is an EFI firmware issue.
No easy fix
One, who was supposedly turned away by Apple Support and told their Mac is “just too old,” was able to obtain a fix from a third-party repairer.
“So I get to unofficial service … and they tested all the hardware and it works great, but didn’t wake up with this motherboard,” they write. “They directly programmed EFI with special tool, and now it works.”
There may be a fix if your Mac is suffering this issue, then. But it’s not a simple one. And it’s likely going to cost you if your Mac is no longer covered by an AppleCare warranty.
There are no reports of another fix yet, as far as we can tell.
A widespread issue?
Fortunately, only a small (but growing) number of Mac users appear to have suffered this problem. It isn’t widespread, and there doesn’t seem to be a single root cause or pattern in particular.
It may be just bad luck, then. A software update that happened to go wrong.
You should contact Apple Support first if you’ve encountered this issue — especially if your Mac is still under warranty. If they can’t help you out for free, a third-party may have a more affordable fix.