gtk-builder-convert crashed with AssertionError in _parse(): Badly formed XML, there is no <glade-interface> tag.

I was going through the tutorial at http://www.micahcarrick.com/gtk-glade-tutorial-part-3.html and received this crash.

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: libgtk2.0-dev 2.24.6-0ubuntu5
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic i686
ApportVersion: 1.23-0ubuntu2
Architecture: i386
Date: Sat Oct 8 17:13:20 2011
ExecutablePath: /usr/bin/gtk-builder-convert
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha i386 (20110803.1)
InterpreterPath: /usr/bin/python2.7
ProcCmdline: python /usr/bin/gtk-builder-convert tutorial.glade tutorial.xml
ProcEnviron:
 SHELL=/bin/bash
 PATH=(custom, user)
 LANG=en_CA.UTF-8
 LANGUAGE=en_CA:en
PythonArgs: ['/usr/bin/gtk-builder-convert', 'tutorial.glade', 'tutorial.xml']
SourcePackage: gtk+2.0
Title: gtk-builder-convert crashed with AssertionError in _parse(): Badly formed XML, there is no <glade-interface> tag.
UpgradeStatus: Upgraded to oneiric on 2011-10-03 (5 days ago)
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