DzFbxExporter crashes every time

How does one use the DzFbxExporter? I have a script which shows the export settings and allows to select the target for the export but every time I run it DS hangs at "Executing Script".
Here is my current version:

var oExportMgr=App.getExportMgr();
//define class name for the exporter
var sClassName="DzFbxExporter";
//find the exporter
var oExporter=oExportMgr.findExporterByClassName(sClassName);
//create settings object
var oSettings=new DzFileIOSettings();

//just use the last path
var sInitialPath=oExportMgr.getExportPath();
//propt user to choose a file
//set title bar, initial path and filter
var sPath=FileDialog.doFileDialog(false,
	"Custom Exporter",
	sInitialPath,
	String("%1(*.%2)")
		.arg(oExporter.getDescription())
		.arg(oExporter.getExtension()));
//export
if(sPath && MainWindow.checkExistingFile(sPath)){
	oExporter.WriteFile(sPath, oSettings);
}