Brother USA Website Instruction for Overcoming the Microsoft Windows 10 Update Error
Thanks, Henry for further comment and links. I've just found a further one that may help!
underlining added:
USB printer port missing after disconnecting printer while Windows 10 (version 1903 or later) is shut down
Applies to: Windows 10, version 1903, all editions Windows 10, version 1909, all editions Windows 10, version 2004, all editions
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Resolution
You can avoid the issue by connecting a powered-on USB printer before starting Windows.
More information
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. We are working to fix the issue in a future version of the operating system.
Last Updated: Jun 11, 2020
If it happens again I'll try that.
Unfortunately, my printer is wifi only.
Jack