In Visual Studio I usually get errors when using 3rd party controls due to the assemblies not being deployed along with the application.
To resolve this, I put copies of the control assemblies in a sub-folder of the project called “References” and then add those files to the references in the project references in the solution explorer using browse.
You can then go to the properties page of the reference and set “Copy Local” to true. This will ensure that the module gets deployed to the “bin” folder of the app.