Universal Windows Platform app registration fails - blocked by AppLocker

Question

Deploying a UWP app locally from Visual Studio 2015 (Update 3) fails with the error message:

DEP0700 : Registration of the app failed. error 0xC000003A: Deployment of package 6dd81a71-9c3a-4204-abaf-886a9b0c29bb_1.0.0.0_x86__kcdnnw7pbsh48 was blocked by AppLocker. (0x80073cf9)

The full output doesn't add further insight:

Restoring NuGet packages...
To prevent NuGet from restoring packages during build, open the Visual Studio Options dialog, click on the Package Manager node and uncheck 'Allow NuGet to download missing packages during build.'
1>------ Build started: Project: App2, Configuration: Debug x86 ------
1>  App2 -> c:\users\<username>\documents\visual studio 2015\Projects\App2\App2\bin\x86\Debug\App2.exe 
2>------ Deploy started: Project: App2, Configuration: Debug x86 ------
2>Updating the layout... 
2>Copying files: Total <1 mb to layout... 
2>Checking whether required frameworks are installed...
2>Registering the application to run from layout... 
2>DEP0700 : Registration of the app failed. error 0xC000003A: Deployment of package 6dd81a71-9c3a-4204-abaf-886a9b0c29bb_1.0.0.0_x86__kcdnnw7pbsh48 was blocked by AppLocker. (0x80073cf9)
========== Build: 1 succeeded, 0 failed, 0 up-to-date, 0 skipped ==========
========== Deploy: 0 succeeded, 1 failed, 0 skipped ==========

This has been created as new project via File > New > Project... > Blank App (Universal Windows), with no other changes being made.

Visual Studio is running as Administrator.

Windows 10 (1607 Build 14393) is set up with Developer mode on.

Other suggestions include deleting the app directory from %LocalAppData%\Packages, but there is no directory corresponding to this app.

What could the issue be here? Is there any advice on next steps to troubleshoot this?

Answer 1

Had this same error popping up with Visual Studio 2017 every time I tried to open a XAML file in UWP project. Fixed it by simply creating the folder C:\Windows\System32\AppLocker.