Index: sources/gui/qml/pages/MainStack.qml
===================================================================
diff -u -r7d2122a9a4330ebc2ff4c22be36f32e9a82417ec -rc62102200fea4a7acdee773156e6647a30d77967
--- sources/gui/qml/pages/MainStack.qml	(.../MainStack.qml)	(revision 7d2122a9a4330ebc2ff4c22be36f32e9a82417ec)
+++ sources/gui/qml/pages/MainStack.qml	(.../MainStack.qml)	(revision c62102200fea4a7acdee773156e6647a30d77967)
@@ -139,8 +139,7 @@
         function onStandbyWaitTreatmentChanged  ( vValue ) { if ( vValue ) vDisinfectAdjustDisinfect.hasCancel  = false             }
         function onStandbyWaitDisinfectChanged  ( vValue ) { page( _disinfectStack                  , vValue    )}
 
-        function onValidateParametersChanged    ( vValue ) {       _preTreatmentCreateStack.clear   ( vValue    ) // vValue == true if enterig the state ( clear only on entering).
-                                                             page( _preTreatmentCreateStack         , vValue    )}
+        function onValidateParametersChanged    ( vValue ) { page( _preTreatmentCreateStack         , vValue    )}
         function onPreTreatmentChanged          ( vValue ) { page( _preTreatmentStack               , vValue    )}
         function onInTreatmentChanged           ( vValue ) { page( _treatmentStack                  , vValue    )}
         function onPostTreatmentChanged         ( vValue ) { page( _postTreatmentStack              , vValue    )}