I had this issue when I had qbittorent running for many days.  top shows hud-service eating 99% cpu.
Closing qbittorrent fixed the issue.  


The ~/.cache/upstart/hud.log 

QDBusError("org.freedesktop.DBus.Error.InvalidArgs", "Unable to find windowId") 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "The name :1.289 was not provided by any .service files" 
QCoreApplication::postEvent: Unexpected null receiver
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "The name :1.304 was not provided by any .service files" 
QCoreApplication::postEvent: Unexpected null receiver
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
QCoreApplication::postEvent: Unexpected null receiver
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
QCoreApplication::postEvent: Unexpected null receiver
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
QCoreApplication::postEvent: Unexpected null receiver
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
QCoreApplication::postEvent: Unexpected null receiver
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
QCoreApplication::postEvent: Unexpected null receiver
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
QCoreApplication::postEvent: Unexpected null receiver
void DBusMenuImporter::slotGetLayoutFinished(QDBusPendingCallWatcher*): "No such object path '/MenuBar/1'" 
QCoreApplication::postEvent: Unexpected null receiver