I was having this problem in 14291 of not being able to run SFC /SCANNOW command for the error of WINDOWS RESOURCE PROTECTION COULD NOT START THE REPAIR SERVICE message..........................After looking in the Feedback App I found the answer to fix that problem. It works in both 14291 and 14295 you just have to tweak the commands to fit your build. Anyway here's how I did it:
RUN SFC /SCANNOW in an administrative command prompt window
Get the error stated above.
Open the CBS.LOG file in the C:\Windows\Logs\CBS\ folder
Check what file it fails to load and make note of the folder it is looking in for the file
run the following commands
takeown /F C:\Windows\WinSxS\amd64_microsoft-windows-servicingstack_31bf3856ad364e35_10.0.14291.1001_none_7c2e5a73f273bd94\*/R /A
icacls C:\Windows\WinSxS\amd64_microsoft-windows-servicingstack_31bf3856ad364e35_10.0.14291.1001_none_7c2e5a73f273bd94\*.* /T /grant administrators:F
xcopy /C /R /O /Y C:\Windows\WinSxS\amd64_microsoft-windows-servicingstack-onecore_31bf3856ad364e35_10.0.14291.1001_none_b11fef854a76db2a\wrpint.dll
C:\Windows\WinSxS\amd64_microsoft-windows-servicingstack_31bf3856ad364e35_10.0.14291.1001_none_7c2e5a73f273bd94
and viola! you can run SFC /SCANNOW without any problems after that