How to resolve "App Engine Studio is not installed on this instance" issue?

I am trying to use my Tokyo PDI to build an app, but there is a banner that reads: "App Engine Studio is not installed on this instance. You can install App Engine Studio by activating the plugin on your instance"

I have painstakingly followed all the steps in the documentation. I have successfully installed and updated App Engine Studio and loaded demo data, and yet I'm still getting the message that App Engine Studio is not installed. Am I doing something wrong, or is it a bug? Once again, I have completely and successfully installed App Engine Studio. 

Please see screenshots. Is there something else that needs to be done?