If you are using Firefox and certain security, HTTPS, or script blocking extensions, you might not be able to use Netflix and get a “Digital Rights Management (DRM) error” such as N8156-6003, N8156-6013, N8156-6023. Many websites say that the solution to the problem is to delete the file “mspr.hds” located at %ProgramData%\Microsoft\PlayReady, but this does not always work because this isn’t always the underlying problem.
The problem is caused by scripts from microsoft.com required to use Silverlight DRM not loading properly. The fix is simple and does NOT require disabling NoScript or HTTPS Everywhere nor does it require restarting Firefox in Safe Mode just to watch Netflix. Make sure that you’re already allowing scripts to run from “netflix.com” and “nflxext.com” as these are also required for Netflix.
For NoScript, visit microsoft.com, open the NoScript menu, and choose “allow microsoft.com” from the list.
For HTTPS Everywhere, open the Add-ons Manager (usually under the Firefox menu, or under Tools -> Add-ons) and beside HTTPS Everywhere, click “options.” Type “microsoft” in the Search box. Look for “Microsoft (partial)” in the list and click the green check beside it to change it to a red “X” instead.
If you are running other script blocking software or extensions, you should be able to find a way to both unblock scripts from as well as don’t force HTTPS on the domains netflix.com, nflxext.com, and microsoft.com.