When I try to run the auto generated code in my google web app project using GAE I get the following error:
Mar 19, 2014 5:21:28 PM com.google.appengine.tool
iQue,
I encountered exactly the same problem, and I discovered that my eclipse was using JRE 8 (version 1.8). I didn't intend this, and when I changed it to 1.7, this solved the problem.
Edit: Window -> Preferences -> Java -> Installed JREs. Checked jre7 to make it default.
Relevant note: The App Engine installation instructions say to use 1.7 (but don't say you can't use 1.8): https://developers.google.com/appengine/docs/java/gettingstarted/installing