Mac Users Warning: macOS Catalina Installation Bricks Mac via EFI Firmware

Several Apple Mac users are recently reporting another issue they encountered when they installed macOS Catalina. Several reports on various online forums suggest that users updating their Macs to macOS Catalina experienced the device becoming non-responsive. There are some indications, though, that an update to the EFI Firmware could be the underlying reason behind the issue.

A small number of Mac users are recently reporting that after upgrading to macOS Catalina, their machines are bricked. Many believe that the issue could be due to the unsuccessful EFI firmware update. Users affected by the recent issue claimed that all they see was nothing but a folder icon when they tried to boot up their Mac.

macOS Catalina, like all other updates released by Apple, has its own fair share of issues. We have recently reported about some Mac users reporting that their device got bricked, but after several updates, it seems to work just fine until recently. There were also reports of apps not working correctly, broken features, and eGPUs not functioning correctly.

Most of the problems that the users are reporting are small but very frustrating. However, those could be easily fixed with future updates. But, the corruption of the EFI firmware is another different story. The Extensible Firmware Interface (EFI) was specially designed by Intel to replace the Open Firmware utilized on PowerPC Macs.

The majority of the reports appear to concern older models of Mac or those released between 2014 and 2015. All the reports share the same story of installing macOS Catalina only to be welcomed by a black screen and the "?folder" icon. One Mac user claimed that he brought his device to an unofficial service center that directly reprogrammed the device’s EFI with a special tool that eventually fixed the issue.

At this point, there is a very small number of users reporting about an issue related to Mac bricking because of EFI Firmware. Although it may seem like an issue, in terms of scale, it appears to be very limited at the moment. If you are experiencing the same problem, you should contact Apple Support first, especially if your Mac is still under warranty.