I downloaded the GCM project from git and i was able to start the server (app engine for java) and also compile the client apk on the device. On startup the device successfully registers with the server and I can see the registration id when i go to http://myserverip:8080/_ah/admin/. The problem is when i hit the 'Send Message' button there is a message 'Single message queued for registration id ' and it doesn't do anything. Below is a screenshot of the error i noticed on the terminal. Am i missing something. Any help is appreciated. Thanks. .