I know that this is not a System Center related post but I just spent the good part of 2 hours pulling my hair out over this issue so I thought I better have something to show for it at the end of it all.
In my lab I had newly built Windows 10 Enterprise PC’s that are joined to a domain. Before they join the domain all apps are functioning fine, however, as soon as one of them joins the domain ALL the Windows 10 packaged apps stop working even the start menu (Cortana) doesn’t work and the Edge browser does not appear on the taskbar.
Now I know I have some AppLocker GPO’s in the environment that prevent users from running applications under their user folder (C:\User\Username) but that does not explain why these apps are not running as they are not run from one of these locations.
Looking at the event logs, the AppLocker event log reads: “No packaged apps can be executed while Exe rules are being enforced and no packaged app rules have been configured”
Under Windows 8.x and 10, the new applications require new AppLocker rules called Package App Rules. These rules target the new Modern UI style apps. If you enable AppLocker with simple .exe based rules, Windows will automatically disable ALL modern apps unless unlocked by specific AppLocker rules.
This seems a simple enough answer. Turn off Applocker in GPO and reboot.
However, after removing the GPO, refreshing the GPO’s (GPUpdate /force) and rebooting several times the error still occurs.
It is almost as if once the Applocker rules are applied they are never removed.
After a little more digging I found this article: Problem: AppLocker Rules Still Enforced After the Service is Stopped
Turns out that when you remove the GPO from workstations the Applocker service gets disabled before it can update it’s policies so the policies remain intact.
Short answer was to keep the GPO’s enabled but remove ALL of the Applocker rules, refresh the GPO’s several times until the Packaged apps start to work again and then you can remove the GPO. So in the end the answer is not to difficult, but unless you go digging in to the fact that modern apps are treated differently by AppLocker and GPO’s will disable the service before cleaning house, then this blog may be useful.