loadModelXML throws an exception

[ToonTalk]

2013-10-04 10:09:01.224
com.allen_sauer.gwt.log.server.ServerLogImplJDK14 log: Uncaught Exception:
com.google.gwt.core.client.JavaScriptException: (TypeError) : Cannot read property
'b' of null
    at uk.ac.lkl.client.BehaviourComposer.$loadModelXML(BehaviourComposer.java:1857)
    at uk.ac.lkl.client.Modeller$16.$onSuccess(Modeller.java:1237)
    at uk.ac.lkl.client.Modeller$16.onSuccess(Modeller.java:1237)
    at com.google.gwt.user.client.rpc.impl.RequestCallbackAdapter.$onResponseReceived(RequestCallbackAdapter.java:198)
    at com.google.gwt.http.client.Request.$fireOnResponseReceived(Request.java:236)
    at com.google.gwt.http.client.RequestBuilder$1.onReadyStateChange(RequestBuilder.java:409)
    at Unknown.eval(0.js@65)

Original issue reported on code.google.com by ToonTalk on 2013-10-04 14:24:44