Running Cache 2017.2.2.

I'm trying to make a REST API call in JSON format. When using the example in the class reference documentation the getJSON method in the %Net.Http class throws the error <METHOD DOES NOT EXIST> on a %Clone() method in the %LIbrary.DynamicObject class. I even changed the parameter to a JSON string to no avail. The code will then fail on the %Compose method (examples below). My workaround is to use the %Net.HttpRequest functionality. Is there another workaround to this?