An exception of type 'System.Resources.MissingManifestResourceException' occurred in mscorlib.dll but was not handled in user code

Additional information: Could not find any resources appropriate for the specified culture or the neutral culture. Make sure "AjaxControlToolkit.Properties.Resources.NET4.resources" was correctly embedded or linked into assembly "AjaxControlToolkit" at compile time, or that all the satellite assemblies required are loadable and fully signed.