As of last week, Windows 10's latest stable build is 10586, replacing 10240 and everyone that cannot defer it will be forced to "upgrade" to that.
On said build, Bitdefender Total Security 2016 appears to interfere with the "/Online" parameter of the DISM command.
For those that don't know of it, the command
DISM /Online /Cleanup-Image /RestoreHealth
will repair a Windows 8/8.1/10 image when it becomes corrupt and the SFC /ScanNow command cannot repair it. Specifically the "/Online" portion tells the DISM command to download the appropriate files directly from the Windows update servers.
With a completely fresh Bitdefender Total Security 2016 installation where absolutely NO settings have been changed from their defaults, the above command after taking several minutes returns an error to the effect of "the sources were not available/could not be downloaded".
Turning off any and all modules, including the firewall makes no difference whatsoever.
After uninstalling Bitdefender, rebooting the system and re-running the above command results in a MUCH faster scan and a positive result:
"The restore operation completed successfully.
The operation completed successfully."
A further SFC scan also returns a "Windows Resource Protection did not find any integrity violations." message.
Unfortunately I have noticed that a corruption occurs after every Windows update with Bitdefender installed and suspect (but cannot be positive) that Bitdefender somehow interferes with the update process and causes the "corruption" which in truth is simply a file mismatch, forcing me to uninstall and reinstall Bitdefender every few days.