Followed "Creating a Project"-guide (eclipse) for Google App Engine - Server error when uploading

[user1885172 via StackOverflow]

To get familiar with Google App Engine I tried to do the Guestbook-example from "Create a Project" getting started guide on Google developer pages. When trying to access the application I get a 500 server error. From the log file in the App Engine Dashboard I get this error:

Uncaught exception from servlet javax.servlet.UnavailableException: Initialization failed. at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.createHandler(AppVersionHandlerMap.java:228) at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.getHandler(AppVersionHandlerMap.java:194) at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:134) at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:447) at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:454) at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:461) at com.google.tracing.TraceContext.runInContext(TraceContext.java:703) at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:338) at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:330) at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:458) at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:251) at java.lang.Thread.run(Thread.java:679)

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