You may have following error message when you start Google App Engine Server.
[note] Initializing App Engine server [ERROR] Unable to start App Engine server java.lang.RuntimeException: Unable to restore the previous TimeZone at com.google.appengine.tools.development.DevAppServerImpl.restoreLocalTimeZone(DevAppServerImpl.java:228) at com.google.appengine.tools.development.DevAppServerImpl.start(DevAppServerImpl.java:164) at com.google.appengine.tools.development.gwt.AppEngineLauncher.start(AppEngineLauncher.java:97) at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:509) at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1068) at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:811) at com.google.gwt.dev.DevMode.main(DevMode.java:311) Caused by: java.lang.NoSuchFieldException: defaultZoneTL at java.lang.Class.getDeclaredField(Class.java:1882) at com.google.appengine.tools.development.DevAppServerImpl.restoreLocalTimeZone(DevAppServerImpl.java:222) ... 6 more [ERROR] shell failed in doStartupServer method [/note]
The solution is to add an extra parameter in your virtual machine run configuration.
[note] -Dappengine.user.timezone=UTC [/note]
References