Problems of following "Hello Deployment" codelab


I am new to Spinnaker and am trying to do the “Hello Deployment” codelab. Stuck in a problem. Hope I can get some help:

My creating for a Spinnaker application failed failed with error " Could not create application: Not Found". Did not find much information about it on Google. Wonder how to debug this issue.

Some details of my setup:
I am literally doing everything exactly in the codelab, and am setting up everything (Halyard, Spinnaker, Jenkins, aptly, nginx) on my personal computer which runs Ubuntu 14.04 LTS, and use GCE as the cloud provider, GCS as the storage.

Thanks very much!