Google Cloud Tutorial - Error Response [3]: Docker image not found


I’m following the Google Cloud tutorial at verbatim - I’ve set up the project at Google Cloud and created a corresponding workspace. Running the project and going to the c9users link works fine, but when I try and deploy, I get this:

[INFO] Updating module [default].../
[INFO] Updating module [default]...-
[INFO] Updating module [default]...failed.
[INFO] ERROR: ( Error Response: [3] Docker image
course.default.20160920t143019 was either not found, or you do not have access to it.

Is there somewhere else I need to enable permissions? I can’t find anything.