System.InvalidOperationException error

[bajanpoet]

had created an application that worked, was deployed and used for a while before someone asked for an addition. When I tried to run the completed executable file, I got a System.InvalidOperationException error immediately. When I opened the source code and tried to run it before making any changes, I got the same error.

System.InvalidOperationException was unhandled Message="An error occurred creating the form. See Exception.InnerException for details. The error is: The NeutralResourcesLanguageAttribute on the assembly \"VanRouter, Version=2.0.0.0, Culture=neutral, PublicKeyToken=null\" specifies an invalid culture name: \"en-CB\"."

What is this and how do i fix it??!!?