A bug in Apple’s macOS software update process is causing problems for Mac system administrators and mobile device management implementations.
As noted by microMDM, the problem surfaced after the release of macOS Big Sur version 11.1. There were many reports that system administrators were unable to see or download and install the software update.
Apparently, the cause of the problem is that macOS 11.0.1 and macOS 11.1 hosts request that update servers send through macOS 11.0.1 instead of the next available software update. Therefore the server rejects the request because 11.0.1 is already installed on a machine.
This particular bug appears to be related to MDM enrollment profiles. Both MicroMDM and other system administrators have confirmed this.
As such, removing the MDM profile should fix the problem. Of course, this is not always an option for certain MDM implementations.
While it may seem like a reboot could fix the problem, there may still be problems downloading the update as the “condition that made it fail the first time could be reactivated”.
Fixing the situation is also compounded by the fact that Apple has stopped providing standalone installers for macOS software updates with Big Sur. Hence, there is no option to manually update to the new version of Big Sur. Updates must come from Apple’s servers.
Other issues include the fact that Apple Silicon eliminates the option for third-party processes to script a software update command.
At this point, Apple is no doubt aware of the issue here. Hence, it is likely that a fix for the problem will come in macOS 11.2.