Update Error E02017, Cannot Use File (Still)

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Unable to launch, update, or anything due to the above error. If I instead try to run a repair, instead of update, I get the same thing. I know this is being mentioned by other people, and the only solutions I've seen posted are either kill the process, or reboot. I've tried both. Furthermore, I've reinstalled Windows 10, due to a different issue with something else entirely, and it made no difference.