Not every AppVM or DispVM must have a valid TemplateVM...

qubesmanager/main.py

@@ -105,7 +105,7 @@ class VmInfoWidget (QWidget):
         layout1 = QHBoxLayout()
 
         if vm.is_appvm() or vm.is_disposablevm():
-            label_tmpl = QLabel ("<i><font color=\"gray\">" + vm.template_vm.name + "</i></font>")
+            label_tmpl = QLabel ("<i><font color=\"gray\">" + (vm.template_vm.name if vm.template_vm is not None else "--") + "</i></font>")
         elif vm.is_template():
             label_tmpl = QLabel ("<i><font color=\"gray\">TemplateVM</i></font>")
         elif vm.qid == 0: