I was in the process of researching something for a friend and came across this June 29, 2016, article in PCWorld: Windows 10 upgrade: Fixes for error code 0x80073712 and missing or damaged files:
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0x80073712: What some users say
Over on the Sysnative forums, one user reported success installing the upgrade from a USB stick instead of using Windows Update before moving onto more desperate measures.
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