I'm trying to install update KB4551762 but for some reason it keeps failing. It always installs 20% but then it suddenly jumps to 100% and fails with error code 0x800f0831 no matter how often I retry.
I've already tried stopping and restarting all the update services, renaming SoftwareDistribution and catroot2, Dism and scannow as advised in the forums but it keeps failing. I also downloaded the update from the Microsoft Update Catalog and tried installing it with the msu installer but this also keeps failing. At first it's fine but when the progress bar reached approximately 20% it also jumps to 100% and fails - just like Windows Update.
I don't have any idea why this happens but I may have an idea. Yesterday, when Windows automatically tried to install the update and it failed for the first time the controlled folder access of the Windows Defender ransomware protection blocked a "VSSVC.exe" and "svchost.exe", two Microsoft services that were probably needed for the installation. Why the built-in AV would block a Microsoft service is beyond me, so I scanned my PC with Defender, Hitman Pro and Malwarebytes and nothing was found. I'm really careful as far as browsing, downloads etc. are concerned so I doubt there's anything malicious on my system, especially after scanning with three AVs (of course they're not always installed, only for 2nd opinion scans after the blocks).
Nevertheless, I thought controlled folder access may have caused the problem, so I turned it off right after the first fail but it keeps failing. Any ideas? I really hope I can install the update soon because it's apparently a quite important security fix.