I know sfc /scannow is definitely not working in 14291; could be dism is having a problem as well.
Insider Announcing Windows 10 Insider Preview Build 14291 for PC and Mobile - Page 15 - Windows 10 Forums
Have a look at these replies from another thread , particularly the one given by DaRKNeTz.
SFC and DISM will not run on build 14279
I have trouble following his "solution", but another member said it worked for him. So, I pass this on to you.
It even worked for me back in 9926, when it didn't work for most, here in the forums.
As you can see DISM online still works for me though.
I'm thinking that Microsoft turned SFC off, because of the false positives it would give for the "New Stuff" like Edge's extensions, and whatever else that needs to be compared in the Windows side-by-side folders and the originals. +
The static files would create false positives like GWX did in the beginning.
Here is what I mean, this is an answer I was giving people in Eight Forums, back last July:
You can try fixing the files by copy & pasting in an Admin Command Prompt:
Dism.exe /online /Cleanup-Image /StartComponentCleanup&sfc/scannow&Dism /Online /Cleanup-Image /RestoreHealth&sfc/scannow&pause
And let it run through then reboot and run it again to check if it cleaned everything.
It may take a while depending on your hardware(HDD or SSD), and it may appear to freeze at 20% on the third part, just be patient and let in run out.
: only 2 false positives will show up(this is the result of the GWX software as Windows has nothing from the original OS software to compare it toŽ) and they are(in red):
SummaryThis update enables the Diagnostics Tracking Service in Windows 8.1, Windows Server 2012 R2, Windows 7 Service Pack 1 (SP1), and Windows Server 2008 R2 SP1. This tracking service collects data about functional issues in Windows.
This update contains the following two manifests that are occasionally updated by the Diagnostic Tracking Service:
The two files are marked as static files in the update. When an advanced user runs the System File Checker Tool (sfc.exe), the files are unintentionally flagged as corrupted. There is no impact or corruption on a device that is running this update, and this issue will be fixed in a later service update.