add:  if (!gServerURI) return; 
context: function SetUpTree(forceToServer){	//dump("SetUpTree()\n");	SetUpRDF();		gSubscribeTree.setAttribute('ref',null);	var folder = GetMsgFolderFromUri(gServerURI);	var server = folder.server;	try {		subscribableServer = server.QueryInterface(Components.interfaces.nsISubscribableServer);		subscribableServer.subscribeListener = MySubscribeListener;		// Turn progress meter on.      	gStatusBar.setAttribute("mode","undetermined");			subscribableServer.populateSubscribeDatasource(null /* eventually, a nsIMsgWindow */, forceToServer);	}	catch (ex) {		dump("failed to populate subscribe ds: " + ex + "\n");	}}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/a83ba9b73b551ad5108a243823c7cdc9b7c5baad/subscribe.js/clean/mailnews/base/resources/content/subscribe.js