Windows Phone 8 - Exception while loading designer

I have Windows 8 Enterprise Edition installed in my Machine. I am facing problem while designing windows phone 8 application development. The designer part throws an exception

System.Exception Package failed updates, dependency or conflict validation. (Exception from HRESULT: 0x80073CF3) at Microsoft.Expression.HostUtility.Platform.AppContainerProcessDomainFactory.CreateDesignerProcess(String applicationPath, String clientPort, Uri hostUri, IDictionary environmentVariables, Int32& processId, Object& processData) at Microsoft.Expression.DesignHost.Isolation.Primitives.ProcessDomainFactory.ProcessIsolationDomain..ctor(ProcessDomainFactory factory, IIsolationBoundary boundary, AppDomainSetup appDomainInfo, FrameworkName targetFramework, String identifier, String baseDirectory) at Microsoft.Expression.DesignHost.Isolation.Primitives.ProcessDomainFactory.CreateIsolationDomain(IIsolationBoundary boundary) at Microsoft.Expression.HostUtility.Platform.AppContainerProcessDomainFactory.CreateIsolationDomain(IIsolationBoundary boundary) at Microsoft.Expression.DesignHost.Isolation.Primitives.IsolationBoundary.Initialize() at Microsoft.Expression.DesignHost.Isolation.Primitives.IsolationBoundary.CreateInstance[T](Type type) at Microsoft.Expression.DesignHost.Isolation.IsolatedExportProvider.Initialize() at Microsoft.VisualStudio.ExpressionHost.Services.VSIsolationService.CreateExportProvider(IIsolationTarget isolationTarget, ICatalogFactory catalogFactory, IExportFilter filter) at Microsoft.Expression.DesignHost.Isolation.IsolationService.CreateLease(IIsolationTarget isolationTarget) at Microsoft.Expression.DesignHost.IsolatedDesignerService.CreateLease(IIsolationTarget isolationTarget, CancellationToken cancelToken, DesignerServiceEntry& entry) at Microsoft.Expression.DesignHost.IsolatedDesignerService.IsolatedDesignerView.CreateDesignerViewInfo(CancellationToken cancelToken) at Microsoft.Expression.DesignHost.Isolation.IsolatedTaskScheduler.InvokeWithCulture[T](CultureInfo culture, Func2 func, CancellationToken cancelToken) at Microsoft.Expression.DesignHost.Isolation.IsolatedTaskScheduler.<>c__DisplayClassa1.b__6() at System.Threading.Tasks.Task`1.InnerInvoke() at System.Threading.Tasks.Task.Execute()

As an additional information, If I am using blend for designing purpose and after some designing I use Visual Studio to open the solution the design loads properly. Looks like the problem is while creating solution using VS2012.

I am trying to figure out the root cause and solution for this problem. Please, help

The error code stands for the following:

The package failed update, dependency, or conflict validation.

Possible causes:

1. The incoming package conflicts with an installed package.
2. A specified package dependency can't be found.
3. The package doesn't support the correct processor architecture. Check the AppXDeployment-Server event log for more info.

Can you:

• Create a Windows Store App and other XAML based applications without the designer having issues?
• Open a WP8 app without the designer having issues?

Does the: PC meet the requirements for the WP8 SDK?

Supported Operating System Windows 8, Windows 8 Pro Operating system type: Windows 8 64-bit (x64) client versions Hardware: 6.5 GB of free hard disk space 4 GB RAM 64-bit (x64) CPU Windows Phone 8 Emulator: Windows 8 Pro edition or greater Requires a processor that supports Second Level Address Translation (SLAT) -Just because the SDK can be installed doesn't mean that it meets the requirements!

• Application have dependencies? If yes: Are they properly references with all the needed assemblies?

Have you:

• Installed all Windows updates + Visual Studio Updates
• Tried a Visual Studio repair

Do the things above an restart You could even try to re-install VS2012

Biggest question is, did it ever work- and if yes, what has changed since then?