Index: sources/gui/qml/main.qml
===================================================================
diff -u -r16a8f25568b4636ebc31e76c86a8031940cc4ad7 -rc62102200fea4a7acdee773156e6647a30d77967
--- sources/gui/qml/main.qml	(.../main.qml)	(revision 16a8f25568b4636ebc31e76c86a8031940cc4ad7)
+++ sources/gui/qml/main.qml	(.../main.qml)	(revision c62102200fea4a7acdee773156e6647a30d77967)
@@ -170,6 +170,7 @@
         onStandbyChanged: {
             if(vTDOpMode.standby) {
                 vTreatmentVitals.doReset()
+                vTreatmentCreate.txCode = ""
             }
         }
     }
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    )}
Index: sources/gui/qml/pages/pretreatment/create/PreTreatmentCreateContent.qml
===================================================================
diff -u -r59bde65da8602112fd3179cedb7b2f2373f3fa01 -rc62102200fea4a7acdee773156e6647a30d77967
--- sources/gui/qml/pages/pretreatment/create/PreTreatmentCreateContent.qml	(.../PreTreatmentCreateContent.qml)	(revision 59bde65da8602112fd3179cedb7b2f2373f3fa01)
+++ sources/gui/qml/pages/pretreatment/create/PreTreatmentCreateContent.qml	(.../PreTreatmentCreateContent.qml)	(revision c62102200fea4a7acdee773156e6647a30d77967)
@@ -42,7 +42,6 @@
 
     function clear () {
         vTreatmentCreate.patientID  = ""
-        vTreatmentCreate.txCode     = ""
         _bloodFlowRateControl           .clear()
         _dialysateFlowRateControl       .clear()
         _durationControl                .clear()
@@ -105,8 +104,6 @@
             vTreatmentCreate.doConfirm                        ()
             _root.editingEnabled = false
         }
-
-        function onDidValidationFail() { vTreatmentCreate.txCode = "" }
     }
 
     Connections {  target: _acidConcentrateAdjustment
Index: sources/view/VTreatmentCreate.cpp
===================================================================
diff -u -rd862dfcd402206e33b314c458e41c13b684a4565 -rc62102200fea4a7acdee773156e6647a30d77967
--- sources/view/VTreatmentCreate.cpp	(.../VTreatmentCreate.cpp)	(revision d862dfcd402206e33b314c458e41c13b684a4565)
+++ sources/view/VTreatmentCreate.cpp	(.../VTreatmentCreate.cpp)	(revision c62102200fea4a7acdee773156e6647a30d77967)
@@ -133,7 +133,7 @@
         emit didValidationFail();
     }
     else {
-        generateTxCode();
+        if ( _txCode.isEmpty()) { generateTxCode(); }
         emit didValidationPass();
     }
 }