Apple fixes macOS Monterey bug that bricked some T2-equipped Macs

Apple has fixed a bug that could cause some Intel Macs with a T2 chip to fail to boot up after macOS Monterey was installed, Apple said in a statement reported by Rene Ritchie on Twitter.

Unveiled at WWDC21, macOS Monterey gives users the power to accomplish more than ever.
macOS Monterey


There was a problem with the firmware on the Apple T2 security chip that prevented some users from being able start their Macs after updating to the ‌macOS Monterey‌ software.

Apple says that a BridgeOS firmware update is now included with the existing macOS updates to prevent further failures, and users already impacted by the issue should contact Apple Support for assistance with their machines.

MacDailyNews Take: M-series-powered Macs were not affected as they do not have a separate T2 chip. Macs with a T2 chip were manufactured between 2017 and 2020, with a list available below.

• Mac mini (2018)
• iMac (Retina 5K, 27-inch, 2020)
• ‌iMac‌ Pro
• Mac Pro (2019)
• ‌Mac Pro‌ (Rack, 2019)
• MacBook Air (Retina, 13-inch, 2018)
• ‌MacBook Air‌ (Retina, 13-inch, 2019)
• ‌MacBook Air‌ (Retina, 13-inch, 2020)
• MacBook Pro (13-inch, 2018, Four Thunderbolt 3 ports)
• MacBook Pro (15-inch, 2018)
• MacBook Pro (13-inch, 2019, Two Thunderbolt 3 ports)
• MacBook Pro (13-inch, 2019, Four Thunderbolt 3 ports)
• MacBook Pro (15-inch, 2019)
• MacBook Pro (16-inch, 2019)
• MacBook Pro (13-inch, 2020, Two Thunderbolt 3 ports)
• MacBook Pro (13-inch, 2020, Four Thunderbolt 3 ports)

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  1. I decided to install the Big Sur 11.6.1 update that was released at the same time as Monterey. Even that update bricked my 2018 15″ MBP. After searching for a couple of days I found an article about restoring the DFU via a USB connection to another Mac and using Apple Configurator 2. It worked like a charm and I’m glad I had another Mac and cable on hand to fix it.

  2. It’s a good thing I have set automatic updates on my MacBook Air. It froze for a week after I installed Monterey . . . Then, one day, it started up fine. 12.0 became 12.01!

  3. WHAT APPLE SAID: “Apple has fixed a bug that could cause some Intel Macs with a T2 chip to fail to boot up after macOS Monterey was installed.”

    WHAT APPLE DID NOT SAY: Apple did not find a bug because we missed the test in older systems.

    Certainly we have known for years how SLOPPY Apple software has become under Clueless Cook. Yeah, it happens for years prior, but the frequency has been escalating. The customer BETRAYAL by Cook scanning our devices has blown up our PRIVACY RIGHTS and must be stopped…

  4. OS Monterey downloaded to Macbook with intel processor fails bluetooth streaming connection. Able to connect bluetooth speaker and airpods when not streaming, bluetooth connection will not work for streaming music or video, although the indicator says bluetooth is connected. Will there be another update to fix this issue?

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