After installing an update, many users have reported that Windows 10 finds files that are damaged and cannot be repaired. Such error messages were displayed by the system file check (sfc). A check can be started by calling the command prompt (cmd.exe) with administrator rights and then running the "sfc / scannow" console command.
In a support message, Microsoft acknowledges that the bug is a known issue with Windows 10 version 1607 or higher and Windows Defender version 4.18.1906.3 or higher. The hash values of some files no longer match the values stored in the WinSxS system folder because Windows Defender has a new update channel. The sfc tool works correctly.
Windows Defender still works
When a fix will be released is not yet known. In the meantime, however, the Windows Defender can be used as normal. All new files are signed with a valid certificate, so that the start of the program is not prevented. Only the stated error messages are executed by the system file check. Microsoft recommends that you ignore the warnings and wait for the update.
For future versions of the Redmond operating system, the problem should no longer occur. The installation files must then be supplied with the latest Windows Defender versions so that no more error messages are generated.
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