The tag 'ViewModelLocator' does not exist in XML namespace clr-namespace:XXX

I have tried numerous other solutions without any success. I have a class called `ViewModelLocator` which is located in my portable class library. It has a property in it called `ViewModels`, which is of type `Dictionay<K, V>` Then I have a Windows Phone 8 project that references the portable class library. I added the following to the WP8 app.xaml: ``` <Application x:Class="Kaizen.WP8.Test.App" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone" xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone" xmlns:test="clr-namespace:Foo.Core.Portable.ViewModel;assembly=Foo.Core.Portable"> <Application.Resources> <test:ViewModelLocator x:Key="ViewModelLocator"> <test:ViewModelLocator.ViewModels> <test:SampleViewModel x:Key="sampleVM"/> </test:ViewModelLocator.ViewModels> </test:ViewModelLocator> </Application.Resources> </Application> ``` When I press F12 on the tags, it navigates to the correct class and or property in my pcl. Which indicates that VS knows about the objects, but when I try and build, I receive the following error: The tag 'ViewModelLocator' does not exist in XML namespace 'clr-namespace:Foo.Core.Portable.ViewModel;assembly=Foo.Core.Portable'. The tag 'SampleViewModel' does not exist in XML namespace 'clr-namespace:Foo.Core.Portable.ViewModel;assembly=Foo.Core.Portable'. Could anyone please provide some assistance? [Update] I reference the pcl version of mvvm light in my pcl project. This is how the `ViewModelLocator` class looks like: ``` public class ViewModelLocator { public dynamic this[string viewModelName] { get { if (this.ViewModels.ContainsKey(viewModelName)) { return this.ViewModels[viewModelName]; } else { return null; } } } public Dictionary<string, ViewModelBase> ViewModels { get; set; } public ViewModelLocator() { this.ViewModels = new Dictionary<string, ViewModelBase>(); } } ``` My WP8 project also makes use of the mvvm light pcl assemblies. I noticed that, if I make use of the `ViewModelBase` class as the dictionary value, that when I get the errors. It's as there's an issue using the mvvm light pcl between the two projects?! [Update] Many thanks in advance!! Kind regards,