Error DEP0700: Registration of the app failed. [0x80073D01] error 0x800704EC: Deployment of package...was blocked by AppLocker

I face an error while developing my first UWP app in VS2017 when trying to debug it:

Error DEP0700: Registration of the app failed. [0x80073D01] error 0x800704EC: Deployment of package 8e2a71c5-f6b4-4f7c-85d5-bf08d20480bf_1.0.0.0_x86__3ckqwrg1r85qm was blocked by AppLocker.

Stack trace on the main page (???): (Update 2018-11-12)

System.Exception The package deployment operation is blocked by policy. Please contact your system administrator. (Exception from HRESULT: 0x80073D01) at Microsoft.VisualStudio.DesignTools.UwpDesignerHost.UwpHostPlatform.<>c__DisplayClass36_0.b__0() at System.Threading.Tasks.Task.InnerInvoke() at System.Threading.Tasks.Task.Execute() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.VisualStudio.DesignTools.DesignerHost.HostServices.HostPlatformBase.d__21.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.VisualStudio.DesignTools.SurfaceDesigner.Documents.SurfaceIsolation.SurfaceProcessContext.d__82.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.VisualStudio.DesignTools.SurfaceDesigner.Documents.SurfaceIsolation.SurfaceProcessContext.d__81.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at Microsoft.VisualStudio.DesignTools.SurfaceDesigner.Documents.SurfaceIsolation.SurfaceProcessContext.d__81.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.VisualStudio.DesignTools.XamlSurfaceDesigner.Views.IsolatedSurfaceImageHost.d__86.MoveNext() --- End of stack trace from previous location where exception was thrown --- at Microsoft.VisualStudio.Telemetry.WindowsErrorReporting.WatsonReport.GetClrWatsonExceptionInfo(Exception exceptionObject)

System.AggregateException One or more errors occurred.

I also have an error message in XAML view:

Visual Studio requires a newer version of Windows to display this content.Please update Windows 10, version 1803 (10.0.17143.0) or later

UPDATE After I followed magicandre1981 advise, I was able to display my XAML properly. I had to lower the "Target Version" of my project properties to a version equal of my Windows 10 or a lower one. But still have DEP0700...

I already have a folder: c:\Windows\System32\AppLocker

In settings/Update & Security/For developers : Use developers features is set to : "Developer mode" but I have a message in red saying:

Developer mode is turned on. However, remote deployment and Windows Device Portal couldn't be installed so they're not available. Error Code 0x800f0954

My windows version is actually:

Windows 10 Enterprise v1709 OS Build: 16299.726

I have administrator rights on my machine but I'm in an enterprise managed with an active directory where GPO's are managed by the security group.

It sounds like it is a GPO problem? Any idea which one?

Note: I got the exact same problem when trying Microsoft Win2D UWP Samples from GitHub.

Note: Someone is suggesting to Close this Question because of a duplicate of another question for which I already refer: Universal Windows Platform app registration fails - blocked by AppLocker. It could not be a duplicate because proposed solution does not fix my bug and the Error code is not the same also.

The problem is due to a policy that was applied on my machine from our company security group.

The GPO is:

Computer Configuration / Administrative Templates / System / Internet Communication Management / Internet Communication settings / Turn off access to the store

It was set to "Enabled" and setting it to "Disabled" solved my problem and I was able to run and debug my application.

Although being able to run the application, I still have the same problem where I can't put my machine in developer mode without error. I still have the error message "Developer mode is turned on. However, remote deployment and Windows Device Portal couln't be installed so they're not available. Error code 0x800f0954" when trying to switch to developer mode in "Settings / Update & Security / For developers"

If I ever got more information, I will write it here.

Update 2019-03-13 Now I can switch to developer mode but I have no idea what was the cause and how it was fixed. Sorry. I'm pretty sure it was another GPO but I have no idea which one.