Cumulative update KB5001330 fails to install

I tried 3 or 4 times to install this update without success. The error message was 0x80073712 on current build 20H2 19042.867 "some update files missing". Tried troubleshooter, DISM restore health etc, all to no avail. Eventually used to windows help link and a Microsoft agent guided me through the installation of a fresh Windows ISO which retained existing apps and files. This was late at night and I eventually went off to bed while the new ISO installed overnight. Next morning all was well and the offending update had installed. Since then no problems and all as it should be. First time I had used the Windows help support and was a bit dubious at first as the agent gets access to your computer to do the necessary tweaks. Must say though I was impressed and delighted to be up to date again although a bit p**d off that the integrity of these updates does not seem to be 100% before they are released.