Big Sur 11.0.1 RC2 Full Installer = “An Error occurred installing macOS”

MrMacintosh.com - macOS Big Sur 11.0.1 RC2 Full Installer.app error = "An Error occurred installing macOS"
macOS Big Sur 11.0.1 RC2 Full Installer.app error = “An Error occurred installing macOS”

When you attempt to install or upgrade on a T2 Mac, you will get the error “The bridgeOS update doesn’t satisfy the given minimum version requirement.”

UPDATE 11/12/20This article is for yesterday’s Big Sur BETA install problem. If you are having problems downloading the new Big Sur update or full installer I have a new article on the issue. It’s for the Installation failed an error occurred while installing the selected updates error.

mrmacintosh.com/big-sur-installation-failed-an-error-occurred-while-installing-the-selected-updates/

Almost immediately after macOS Big Sur 11.0.1 (20B28) was released, I started to see reports of install issues. This was only happening on T2 Macs that need a BridgeOS update. A BridgeOS update is included and required with almost every combo, delta and full installer upgrade or install. Below is the 11.0.1 RC2 Install error.

MrMacintosh.com - An error occurred installing macOS. You can try again to complete the installation.
The error message that you will get if you try to upgrade a T2 Catalina or Big Sur Mac to 11.0.1 RC2

An error occurred installing macOS. You can try again to complete the installation.

Mr. Macintosh video that goes over the issue.

The problem is the new production Software Update Catalog URL does not have the needed BridgeOS update yet.

The problem comes down to the installer looking to the new production SUS url. Apple just made the production SUS catalog available. The new URL is

New Big Sur Production SUS URL =

https://swscan.apple.com/content/catalogs/others/index-11-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog

Big Sur Beta SUS URL =

https://swscan.apple.com/content/catalogs/others/index-10.16seed-10.16-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog

The production URL does NOT include the required BridgeOS update needed for the Big Sur RC2 installer to continue.

The BridgeOS error from install.log

This is the error that you will get.

/var/log/install.log

bridgeOS update prepare complete
2020-11-11 01:49:05-06 osinstallersetupd[5967]: bridgeOS update prepare failed: Error Domain=BOSErrorDomain Code=110 "The bridgeOS update doesn't satisfy the given minimum version requirement." UserInfo={bridgeVersion=17.16.16610.0.0,0, minimumVersion=18.16.12561.0.0,0, catalogURL=https://swscan.apple.com/content/catalogs/others/index-11-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog, NSLocalizedDescription=The bridgeOS update doesn't satisfy the given minimum version requirement.}
2020-11-11 01:49:05-06 osinstallersetupd[5967]: Operation queue failed with error: Error Domain=com.apple.OSInstallerSetup.error Code=602 "An error occurred installing macOS." UserInfo={NSLocalizedRecoverySuggestion=You can try again to complete the installation., NSLocalizedDescription=An error occurred installing macOS., NSUnderlyingError=0x7fde25b85770 {Error Domain=BOSErrorDomain Code=110 "The bridgeOS update doesn't satisfy the given minimum version requirement." UserInfo={bridgeVersion=17.16.16610.0.0,0, minimumVersion=18.16.12561.0.0,0, catalogURL=https://swscan.apple.com/content/catalogs/others/index-11-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog, NSLocalizedDescription=The bridgeOS update doesn't satisfy the given minimum version requirement.}}}
2020-11-11 01:49:05-06 InstallAssistant[5928]: Stopped operation queue with Error Domain=com.apple.OSInstallerSetup.error Code=602 "An error occurred installing macOS." UserInfo={NSUnderlyingError=0x7fd70cf90da0 {Error Domain=BOSErrorDomain Code=110 "The bridgeOS update doesn't satisfy the given minimum version requirement." UserInfo={bridgeVersion=17.16.16610.0.0,0, minimumVersion=18.16.12561.0.0,0, catalogURL=https://swscan.apple.com/content/catalogs/others/index-11-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog, NSLocalizedDescription=The bridgeOS update doesn't satisfy the given minimum version requirement.}}, NSLocalizedRecoverySuggestion=You can try again to complete the installation., NSLocalizedDescription=An error occurred installing macOS.}

Notice this line

The bridgeOS update doesn’t satisfy the given minimum version requirement.” UserInfo={bridgeVersion=17.16.16610.0.0,0, minimumVersion=18.16.12561.0.0,0, catalogURL=https://swscan.apple.com/content/catalogs/others/index-11-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog

I track all T2 BridgeOS updates here >

mrmacintosh.com/macos-system-status-version-info-for-macadmins

This is what the new Big Sur 11 production SUS looks like right now.

MrMacintosh.com - Big Sur 11.0.1 RC2 SUS Production url.
Big Sur 11.0.1 RC2 SUS Production url.

Notice how the Big Sur 11.0.1 RC2 BridgeOS update is not showing up. This is why you are getting the error.

Below is what the Big Sur DeveloperSeed Catalog looks like.

MrMacintosh.com - Big Sur 11.0.1 RC2 SUS Beta url.
Big Sur 11.0.1 RC2 SUS Beta url.

The Big Sur DeveloperSeed catalog has the 11.0.1 RC2 BridgeOS update!

Now that we know what the problem is, what can we do about it?

Set the SUS server to the DeveloperSeed SUS URL.

To resolve this issue we can use the nvram binary to set the SUS catalog to the correct one that has the BridgeOS update that we need.

sudo nvram IASUCatalogURL=https://swscan.apple.com/content/catalogs/others/index-10.16seed-10.16-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog

You can use sudo nvram -p to view all the nvram settings.

NOTE! When you are done with the upgrade, don’t forget to remove the value!

sudo nvram -d IASUCatalogURL

MacAdmins at work!

It’s amazing to see MacAdmins working together to solve an issue. Yesterday afternoon a bunch of Admins including @golby, @eholtam, @owen, @dave.shepp, @macmule, @matt_h and @deets jumped in to help figure this out and pass on the information to others.

11.0.1 RC2 Install error

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6 thoughts on “Big Sur 11.0.1 RC2 Full Installer = “An Error occurred installing macOS””

  1. Thank you for the details; my install of 11.01 RC2 on a MacBook Air 2020 with a T2 chip made it through to a screen that appeared to require a firmware update (something about a volume not working with the upgraded version of macOS) which appears to have installed correctly.

    But when the machine rebooted, it got about 1/3 of the way through the standard black and white progress bar and then reboots. On some macOS installs, I know the machine has to restart a few times, but after the fifth restart I knew it was stuck in a loop.

    I ran safe mode and it seems to be stopping on an error that mentions SMC not being supported on the machine and then forces a reboot. If I run it in Recovery mode and try to reinstall the Big Sur beta it offers, it then tells me I can’t downgrade the machine.

    As a last resort, I tried your command from within Reovery’s Terminal app (won’t allow sudo, since it doesn’t recognize that as a command) but after typing the script without sudo it took it.

    Yet the loop persists. Any ideas on how to get around the SMC issue? I guess I could delete the APFS container for the EFI but that could cause other issues…

  2. “An error occurred installing macOS” happens reliably when I install with wireless turned off. If I turn wireless on, this error doesn’t appear, but the process hangs at the same spot (about 40% progress) and no disk or network I/O in the activity monitor.

    With enough retries and wireless turned on, it eventually succeeded, and is booting the installed partition. (I’m waiting for the configuration prompts now; 30 mins estimated.)

  3. Just updated to 11.0.1 and youtube no longer works across all browsers. Vimeo etc work but just not Youtube, weird bug!

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