Reference WPF custom control library to a VSIX project

I have a WPF Custom control project and a VSIX project in my solution. THe WPF holds the UI windows and controls that are required both by the VSIX and another WPF app that can be used separately from the VS extension.

I have added the project as a dependency in source.extension.vsixmanifest like so:

<Asset Type="Microsoft.VisualStudio.Assembly" d:Source="Project" d:ProjectName="StringsRefactor.UI" Path="|StringsRefactor.UI|" AssemblyName="|StringsRefactor.UI;AssemblyName|" />

the code compiles but during runtime when i consturct the required object from thr StringsRefactor.UI assembly i get the following error:

Could not load file or assembly 'StringsRefactor.UI, Version=1.0.0.0, Culture=neutral, PublikKeyToken=null' or one of its dependencies. A strongly-named assembly is required. (Exception from HRESULT: 0x80131044)

How should i create a strongly-named assembly? Or should i do something else ?

Simply sign your WPF assembly, it is required by Visual Studio