Construct makes an indirect reference to assembly '<assemblyname>', which contains '<typename>'
Error MessageConstruct makes an indirect reference to assembly '<assemblyname>', which contains <typename>. Add a file reference to <filename> to your project.
An expression uses a type, such as a class, structure, interface, enumeration, or delegate, but your assembly does not have a project reference to the assembly defining the type.
Error ID: BC31528
To correct this error
In your project properties, add a reference to the file containing the assembly that defines the type you are using.