Index: sources/gui/qml/pages/MainStack.qml
===================================================================
diff -u -r689177edf29dee6f10bebfed42f6bbadeb7ce8a8 -rb34af342449705923783d041ec0fa468d1d30be2
--- sources/gui/qml/pages/MainStack.qml	(.../MainStack.qml)	(revision 689177edf29dee6f10bebfed42f6bbadeb7ce8a8)
+++ sources/gui/qml/pages/MainStack.qml	(.../MainStack.qml)	(revision b34af342449705923783d041ec0fa468d1d30be2)
@@ -156,7 +156,8 @@
         function onStandbyWaitTreatmentChanged  ( vValue ) { /* It depends on the subModes of the standBy. Handled by onHome.  */   }
         function onStandbyWaitDisinfectChanged  ( vValue ) { page( _disinfectStack                  , vValue    )}
 
-        function onValidateParametersChanged    ( vValue ) { page( _preTreatmentCreateStack         , vValue    )}
+        function onValidateParametersChanged    ( vValue ) {       _preTreatmentCreateStack         . clear    ()
+                                                             page( _preTreatmentCreateStack         , vValue    )}
         function onPreTreatmentChanged          ( vValue ) { page( _preTreatmentStack               , vValue    )}
         function onInTreatmentChanged           ( vValue ) { page( _treatmentStack                  , vValue    )}
         function onPostTreatmentChanged         ( vValue ) { page( _postTreatmentStack              , vValue    )}