Developing a VB.Net VSIX package System.InvalidCastException: [A] cannot be cast to [B] error

Hi, the last months I've been developing some VSIX packages for VB.NET. Yesterday I started getting a weird error: 

"Type A originates from 'xxxxx, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' in the context  'LoadNeither' at location 'C:\Users\xxxxx\AppData\Local\Microsoft\VisualStudio\10.0Exp\ProjectAssemblies\-jqp5pix01\xxxxx.dll'. 

Type B originates from 'xxxxx, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' in the context 'LoadFrom' at location 'C:\Users\xxxxx\AppData\Local\Microsoft\VisualStudio\10.0Exp\Extensions\...\1.0\xxxxx.dll'."

In my case this problem occurred because both the package and the solution opened in the experimental instance use the same dll. In my package the dll reference was set to copy local. This causes the dll to be copied to: 'C:\Users\xxxxx\AppData\Local\Microsoft\VisualStudio\10.0Exp\Extensions\...\xxxxx.dll'

The solution I open in the experimental instance creates all the folders under: 'C:\Users\xxxxx\AppData\Local\Microsoft\VisualStudio\10.0Exp\ProjectAssemblies\'  and copies all the dll's needed for the solution to this location. The dll's however are created with a date created of when they were copied. This causes the debugger to think that it are two different dll versions. Setting the copy local property of the dll to false can solve your problem.