Verbesserung von Validierungen und State-Management

Die Änderungen umfassen:
- Hinzufügen der Methode `Reset_Current` in `frmMain` zur zentralisierten Rücksetzung von Zuständen.
- Erweiterung von `Item_Scope` mit Validierungen für ungültige Klicks und Fallback-Logik bei DevExpress-Bugs.
- Verbesserte Fehlerbehandlung und Validierungen im `DoubleClick`- und `MouseDown`-Handler.
- Einführung der Methode `ParseColorString` zur sicheren Verarbeitung von Farbwerten.
- Optimierung von `TreeList_Cockpit_DoubleClick` mit Debugging-Logs und State-Reset.
- Hinzufügen von State-Reset-Logik in `frmValidator` (`previousLUSelectedValues`, `hadPreviousLUSelection`).
- Verbesserte Sicherung und Wiederherstellung von Lookup-Werten in `FillIndexValues`.
- SQL-Optimierung: Löschen von Einträgen in `TBTF_PROFILE_FILES_WORK`.
- Erweiterte Debugging-Informationen und Fehlerbehandlung in mehreren Methoden.

app/TaskFlow/frmMain.vb

@@ -2492,6 +2492,14 @@ Public Class frmMain
             End If
         End Try
     End Sub
+    Private Sub Reset_Current()
+        CURRENT_JUMP_DOC_GUID = 0
+        CURRENT_DOC_GUID = 0
+        CURRENT_DOC_ID = 0
+        CURRENT_ProfilGUID = 0
+        CURRENT_CLICKED_PROFILE_ID = 0
+        DT_CURR_WF_ITEMS.Clear()
+    End Sub
     Private Async Function Item_Scope(startedFrom As String) As Task
         ' ========== FRÜHE VALIDIERUNGEN (VOR UI-ÄNDERUNGEN) ==========
         If Application.OpenForms().OfType(Of frmValidator).Any Then
@@ -2514,16 +2522,33 @@ Public Class frmMain
 
         Try
             LOGGER.Info("Starting Profile Loading")
+            Reset_Current()
 
             ' ========== UI-VORBEREITUNG ==========
             Me.UseWaitCursor = True
             useWaitCursorApplied = True
             bsiMessage.Caption = "Processing selection..."
             messageApplied = True
-
             ' ========== HITINFO NUR EINMAL BERECHNEN ==========
             Dim hitInfo As GridHitInfo = GridViewWorkflows.CalcHitInfo(GridCursorLocation)
 
+            ' ===== FRÜHE VALIDIERUNG: UNGÜLTIGE ROWHANDLES ABFANGEN =====
+            If hitInfo.RowHandle = DevExpress.XtraGrid.GridControl.InvalidRowHandle Then
+                LOGGER.Warn($"⚠️ Item_Scope: InvalidRowHandle detected (click on empty grid area?) - exiting")
+                Exit Function
+            End If
+
+            ' ===== ZUSÄTZLICH: Prüfen ob überhaupt eine Zeile getroffen wurde =====
+            If Not hitInfo.InRow Then
+                LOGGER.Warn($"⚠️ Item_Scope: Click not in any row (HitTest:[{hitInfo.HitTest}]) - exiting")
+                Exit Function
+            End If
+
+            ' ===== STARTEDROM NORMALISIEREN =====
+            If startedFrom = "DOUBLECLICK" Then
+                startedFrom = If(hitInfo.InGroupRow, "CMGROUP", "CMROW")
+                LOGGER.Debug($"User clicked {If(hitInfo.InGroupRow, "group", "normal")} row.")
+            End If
             ' ========== STARTEDROM NORMALISIEREN ==========
             If startedFrom = "DOUBLECLICK" Then
                 startedFrom = If(hitInfo.InGroupRow, "CMGROUP", "CMROW")
@@ -2531,21 +2556,56 @@ Public Class frmMain
             End If
 
             ' ========== PROFIL-ID ERMITTELN (OPTIMIERT) ==========
+            ' ========== PROFIL-ID ERMITTELN (MIT FALLBACK-LOGIK) ==========
             Dim oHitProfilID As Object = Nothing
+
+            ' ===== SCHRITT 1: Direkte Erkennung versuchen =====
             If hitInfo.InGroupRow Then
+                ' ✅ Gruppenkopf: Profil-ID aus erster Datenzeile der Gruppe
                 oHitProfilID = GridViewWorkflows.GetRowCellValue(
                 GridViewWorkflows.GetDataRowHandleByGroupRowHandle(hitInfo.RowHandle),
                 GridViewWorkflows.Columns("PROFILE_ID"))
+                LOGGER.Debug("Clicked on Group Row")
+
             ElseIf hitInfo.InDataRow Then
+                ' ✅ Normale Datenzeile: Profil-ID direkt aus dieser Zeile
                 oHitProfilID = GridViewWorkflows.GetRowCellValue(
-                GridViewWorkflows.GetDataRowHandleByGroupRowHandle(
+                hitInfo.RowHandle,
-                    GridViewWorkflows.GetParentRowHandle(hitInfo.RowHandle)),
                 GridViewWorkflows.Columns("PROFILE_ID"))
+                LOGGER.Debug("Clicked on Data Row")
+
+            Else
+                ' ===== SCHRITT 2: FALLBACK für "unklare" Klicks =====
+                ' Wenn hitInfo weder InGroupRow noch InDataRow ist, RowHandle direkt prüfen
+                LOGGER.Warn($"⚠️ hitInfo ist WEDER InGroupRow noch InDataRow - RowHandle:[{hitInfo.RowHandle}]")
+
+                If GridViewWorkflows.IsGroupRow(hitInfo.RowHandle) Then
+                    ' Es ist doch eine Gruppe (DevExpress Bug-Workaround)
+                    LOGGER.Debug("Fallback: IsGroupRow(RowHandle) = True")
+                    oHitProfilID = GridViewWorkflows.GetRowCellValue(
+                    GridViewWorkflows.GetDataRowHandleByGroupRowHandle(hitInfo.RowHandle),
+                    GridViewWorkflows.Columns("PROFILE_ID"))
+
+                ElseIf GridViewWorkflows.IsDataRow(hitInfo.RowHandle) Then
+                    ' Es ist doch eine Datenzeile (DevExpress Bug-Workaround)
+                    LOGGER.Debug("Fallback: IsDataRow(RowHandle) = True")
+                    oHitProfilID = GridViewWorkflows.GetRowCellValue(
+                    hitInfo.RowHandle,
+                    GridViewWorkflows.Columns("PROFILE_ID"))
+
+                Else
+                    LOGGER.Error($"⚠️ RowHandle [{hitInfo.RowHandle}] ist weder Group noch DataRow!")
+                End If
             End If
 
             LOGGER.Debug("Clicked ProfileId: [{0}], Started From: [{1}]", oHitProfilID, startedFrom)
-
+            ' ========== PROFIL-ID VALIDIERUNG ==========
-            ' ========== PROFIL-ID VALIDIERUNG UND UPDATE ==========
+            If oHitProfilID Is Nothing OrElse Not IsNumeric(oHitProfilID) OrElse CInt(oHitProfilID) = 0 Then
+                LOGGER.Warn("⚠️ Item_Scope: Could not determine valid PROFILE_ID from clicked row!")
+                FormHelper.ShowInfoMessage("Konnte keine gültige Profil-ID ermitteln!", omsgTitleWarning)
+                Exit Function
+            End If
+            ' ========== PROFIL-ID UPDATE ==========
             If oHitProfilID IsNot Nothing AndAlso IsNumeric(oHitProfilID) AndAlso CInt(oHitProfilID) > 0 Then
                 If oHitProfilID <> CURRENT_CLICKED_PROFILE_ID Then
                     LOGGER.Debug($"Item_Scope: oHitProfilID {oHitProfilID} <> CURRENT_CLICKED_PROFILE_ID {CURRENT_CLICKED_PROFILE_ID}")
@@ -2748,9 +2808,7 @@ Public Class frmMain
 
                 If hitInfo.InGroupRow OrElse (startedFrom = "CMGROUP" AndAlso hitInfo.InDataRow) Then
                     ' GRUPPE: Workflow ohne spezifisches Dokument
-                    CURRENT_JUMP_DOC_GUID = 0
+                    Reset_Current()
-                    CURRENT_DOC_GUID = 0
-                    CURRENT_DOC_ID = 0
                     CURRENT_ProfilGUID = CURRENT_CLICKED_PROFILE_ID
                     LOGGER.Debug($"Item_Scope: hitInfo.InGroupRow...CURRENT_CLICKED_PROFILE_ID [{CURRENT_CLICKED_PROFILE_ID}]")
                     Load_Profil_from_Grid(CURRENT_CLICKED_PROFILE_ID)
@@ -3315,9 +3373,38 @@ Public Class frmMain
     End Function
 
     Private Async Sub GridViewWorkflows_DoubleClick(sender As Object, e As EventArgs) Handles GridViewWorkflows.DoubleClick
-        Me.Cursor = Cursors.WaitCursor
+        Try
-        Await Item_Scope("DOUBLECLICK")
+            ' ===== KRITISCH: HitInfo MIT AKTUELLEM Mauszeiger-Position berechnen =====
-        Me.Cursor = Cursors.Default
+            Dim oCurrentMousePosition As System.Drawing.Point = GridControlWorkflows.PointToClient(Cursor.Position)
+            Dim hitInfo As GridHitInfo = GridViewWorkflows.CalcHitInfo(oCurrentMousePosition)
+
+            ' ===== FRÜHE VALIDIERUNG =====
+            If hitInfo.RowHandle = DevExpress.XtraGrid.GridControl.InvalidRowHandle Then
+                LOGGER.Warn("⚠️ DoubleClick: InvalidRowHandle - ignoring")
+                Exit Sub
+            End If
+
+            If Not hitInfo.InRow Then
+                LOGGER.Warn("⚠️ DoubleClick: Not in row - ignoring")
+                Exit Sub
+            End If
+
+            ' ===== AKTUALISIERTE GridCursorLocation SETZEN =====
+            GridCursorLocation = oCurrentMousePosition
+
+            LOGGER.Debug($"DoubleClick: RowHandle=[{hitInfo.RowHandle}], InGroupRow=[{hitInfo.InGroupRow}], InDataRow=[{hitInfo.InDataRow}]")
+
+            Me.Cursor = Cursors.WaitCursor
+            Try
+                Await Item_Scope("DOUBLECLICK")
+            Finally
+                Me.Cursor = Cursors.Default
+            End Try
+
+        Catch ex As Exception
+            LOGGER.Error(ex)
+            Me.Cursor = Cursors.Default
+        End Try
     End Sub
 
     'Private Sub GridViewWorkflows_CustomDrawGroupRow(sender As Object, e As Views.Base.RowObjectCustomDrawEventArgs) Handles GridViewWorkflows.CustomDrawGroupRow
@@ -3372,7 +3459,6 @@ Public Class frmMain
 
     Private Sub GridViewWorkflows_CustomDrawGroupRow(sender As Object, e As Views.Base.RowObjectCustomDrawEventArgs) Handles GridViewWorkflows.CustomDrawGroupRow
         Try
-
             If FormOpenClose = True And GridIsLoaded = False Then
                 Exit Sub
             End If
@@ -3387,11 +3473,27 @@ Public Class frmMain
             If oInfo.Column.FieldName = "GROUP_TEXT" Then
                 oInfo.GroupText = oInfo.GroupValueText
 
+                ' ===== PRÜFUNG AUF KINDERZEILEN HINZUFÜGEN =====
+                Dim oChildCount As Integer = oView.GetChildRowCount(oInfo.RowHandle)
+
+                ' Wenn keine Kinder vorhanden sind, Standard-Farben verwenden
+                If oChildCount = 0 Then
+                    LOGGER.Debug($"CustomDrawGroupRow: Group [{oInfo.GroupValueText}] has no children - using default colors")
+                    oInfo.Appearance.BackColor = Color.LightGray
+                    oInfo.Appearance.ForeColor = Color.Black
+                    Exit Sub
+                End If
+
+                ' ===== NUR BEI VORHANDENEN KINDERN FARBE AUSLESEN =====
                 Dim oColorString As String = "LightGray"
                 Dim oFontColorString As String = "Black"
                 Dim oChildRowHandle As Integer = oView.GetChildRowHandle(oInfo.RowHandle, 0)
 
-                oColorString = oView.GetRowCellValue(oChildRowHandle, "GROUP_COLOR")
+                ' GetRowCellValue kann Nothing zurückgeben, daher absichern
+                Dim oCellValue As Object = oView.GetRowCellValue(oChildRowHandle, "GROUP_COLOR")
+                If oCellValue IsNot Nothing AndAlso Not IsDBNull(oCellValue) Then
+                    oColorString = oCellValue.ToString()
+                End If
 
                 Dim oColor As Color = ParseColorString(oColorString, Color.LightGray, "Background Color")
                 Dim oFontColor As Color = ParseColorString(oFontColorString, Color.Black, "Font Color")
@@ -3405,6 +3507,11 @@ Public Class frmMain
     End Sub
 
     Private Function ParseColorString(ColorString As String, DefaultColor As Color, ColorDescription As String) As Color
+        ' ===== NULL-CHECK HINZUFÜGEN =====
+        If String.IsNullOrWhiteSpace(ColorString) Then
+            LOGGER.Debug($"ParseColorString: ColorString is null/empty for {ColorDescription} - using default color")
+            Return DefaultColor
+        End If
         Dim oResultColor As Color
 
         If ColorString.Contains(";") Or ColorString.Contains(".") Then
@@ -3439,6 +3546,17 @@ Public Class frmMain
         Dim view As GridView = sender
         Dim hi As GridHitInfo = view.CalcHitInfo(e.Location)
         Dim groupRowButtonClicked = (hi.HitTest = GridHitTest.RowGroupButton)
+        ' ===== UNGÜLTIGE CLICKS ABFANGEN =====
+        If hi.RowHandle = DevExpress.XtraGrid.GridControl.InvalidRowHandle Then
+            LOGGER.Debug("MouseDown: InvalidRowHandle - ignoring click")
+            Exit Sub
+        End If
+
+        If Not hi.InRow Then
+            LOGGER.Debug($"MouseDown: Click not in row (HitTest:[{hi.HitTest}]) - ignoring")
+            Exit Sub
+        End If
+
         GridCursorLocation = e.Location
 
         'If e.Button = MouseButtons.Left Then
@@ -3449,18 +3567,21 @@ Public Class frmMain
             GridViewItem_Clicked = "GROUP"
             If Not Application.OpenForms().OfType(Of frmValidator).Any Then
                 CURRENT_CLICKED_PROFILE_ID = GridViewWorkflows.GetRowCellValue(GridViewWorkflows.GetDataRowHandleByGroupRowHandle(hi.RowHandle), GridViewWorkflows.Columns("PROFILE_ID"))
+                LOGGER.Debug($"MouseDown: PROFILE_ID for GroupRow [{hi.RowHandle}] is [{CURRENT_CLICKED_PROFILE_ID}]")
             End If
 
         ElseIf hi.InDataRow Then
             GridViewItem_Clicked = "ROW"
             If Not Application.OpenForms().OfType(Of frmValidator).Any Then
                 CURRENT_CLICKED_PROFILE_ID = GridViewWorkflows.GetRowCellValue(GridViewWorkflows.GetDataRowHandleByGroupRowHandle(hi.RowHandle), GridViewWorkflows.Columns("PROFILE_ID"))
+                LOGGER.Debug($"MouseDown: PROFILE_ID for DataRow [{hi.RowHandle}] is [{CURRENT_CLICKED_PROFILE_ID}]")
             End If
 
         Else
             GridViewItem_Clicked = Nothing
             If hi.HitTest = GridHitTest.FilterPanelCloseButton Then
                 Ev_Filter_Panel_Closed = True
+                LOGGER.Debug("MouseDown: FilterPanelCloseButton clicked - Ev_Filter_Panel_Closed set to True")
                 Grid_Reset_Filter()
                 Ev_Filter_Panel_Closed = False
             End If
@@ -3471,6 +3592,7 @@ Public Class frmMain
                     For Each orow As DataRow In CURRENT_DT_PROFILES.Rows
                         If orow.Item("GUID") = CURRENT_CLICKED_PROFILE_ID Then
                             If Not Application.OpenForms().OfType(Of frmValidator).Any Then
+                                LOGGER.Debug($"MouseDown: PROFILE_TITLE for PROFILE_ID [{CURRENT_CLICKED_PROFILE_ID}] is [{orow.Item("TITLE")}]")
                                 CURRENT_CLICKED_PROFILE_TITLE = orow.Item("TITLE")
                             End If
 
@@ -4972,10 +5094,10 @@ FROM VWPM_PROFILE_ACTIVE T WHERE T.GUID IN (SELECT PROFILE_ID FROM [dbo].[FNPM_G
 
                 Dim oProfileId As Integer = CInt(oFkProfileId)
                 LOGGER.Debug($"TreeList_Cockpit_DoubleClick: Opening validator for profile ID [{oProfileId}]")
-
+                Reset_Current()
                 ' ===== PROFIL-DATEN INS GRID LADEN (FALLS NOCH NICHT GELADEN) =====
                 ' Wenn das Grid aktuell leer ist oder ein anderes Profil zeigt, müssen wir erst laden
-                If GRID_LOAD_TYPE <> $"PROFILE#{oProfileId}" OrElse DT_CURR_WF_ITEMS Is Nothing OrElse DT_CURR_WF_ITEMS.Rows.Count = 0 Then
+                If DT_CURR_WF_ITEMS Is Nothing OrElse DT_CURR_WF_ITEMS.Rows.Count = 0 Then
                     LOGGER.Debug($"TreeList_Cockpit_DoubleClick: Grid does not show profile [{oProfileId}] - loading it first")
 
                     CURRENT_CLICKED_PROFILE_ID = oProfileId
@@ -5001,6 +5123,8 @@ FROM VWPM_PROFILE_ACTIVE T WHERE T.GUID IN (SELECT PROFILE_ID FROM [dbo].[FNPM_G
                         FormHelper.ShowInfoMessage(omsg, omsgTitleAttention)
                         Exit Sub
                     End If
+                Else
+                    LOGGER.Debug($"TreeList_Cockpit_DoubleClick: Grid already shows profile [{CURRENT_CLICKED_PROFILE_ID}] with [{DT_CURR_WF_ITEMS.Rows.Count}] items")
                 End If
 
                 ' ===== DOCIDS AUS DT_CURR_WF_ITEMS SAMMELN =====

app/TaskFlow/frmValidator.vb

@@ -142,11 +142,12 @@ Public Class frmValidator
     Private _overlayLock As New Object()     ' ← NEU: Thread-Safe Lock
     Private _documentPathHandler As DocumentPathHandler
     Private _isLoadingAdditionalSearches As Boolean = False
-
     Private _separateGridDataCache As New Dictionary(Of String, DataTable)
     ' Bei den anderen Private-Deklarationen:
     Private _separateGridControlCache As New Dictionary(Of String, GridControl)
-
+    ' ========== BUGFIX START: Alte SelectedValues SICHERN bevor DataSource überschrieben wird ==========
+    Private previousLUSelectedValues As List(Of String) = Nothing
+    Private hadPreviousLUSelection As Boolean = False
 
     Private Class Translation_Strings
         Inherits My.Resources.frmValidator_Strings
@@ -816,9 +817,9 @@ Public Class frmValidator
             End If
 
             Try
-                Dim oSQL As String
+                Dim oSQL = $"DELETE FROM TBPM_DOCWALKOVER WHERE UserID = {USER_ID};" & vbCrLf &
-                oSQL = $"DELETE FROM TBPM_DOCWALKOVER WHERE UserID = {USER_ID};" & vbCrLf &
+                    $"DELETE FROM TBPM_VALIDATION_PROFILE_GROUP_USER WHERE UserID = {USER_ID};" & vbCrLf &
-                $"DELETE FROM TBPM_VALIDATION_PROFILE_GROUP_USER WHERE UserID = {USER_ID};"
+                    $"DELETE FROM TBTF_PROFILE_FILES_WORK WHERE Action_UserID = {USER_ID};"
                 DatabaseFallback.ExecuteNonQueryECM(oSQL)
             Catch ex As Exception
                 MyValidationLogger.Error(ex)
@@ -903,6 +904,9 @@ Public Class frmValidator
         If Not IsNothing(DT_AdditionalSearches_Resultset_Docs) Then
             DT_AdditionalSearches_Resultset_Docs.Clear()
         End If
+        ' Lookup-State zurücksetzen
+        previousLUSelectedValues = Nothing
+        hadPreviousLUSelection = False
     End Sub
 
     Private Sub CleanupTempFolder()
@@ -1788,7 +1792,9 @@ Public Class frmValidator
                     End If
             End Select
         Next
-
+        ' Lookup-State zurücksetzen
+        previousLUSelectedValues = Nothing
+        hadPreviousLUSelection = False
         Focus_FirstControl()
     End Sub
 
@@ -3799,7 +3805,7 @@ Public Class frmValidator
                 oBIT = 1
             End If
             Dim oSQL = $"EXEC PRPM_GET_NEXT_DOC_INFO {CURRENT_ProfilGUID},{CURRENT_DOC_ID},{USER_ID}"
-
+            MyValidationLogger.Debug($"Get_Next_GUID: SQL [{oSQL}]...")
             Dim oDT As DataTable = DatabaseFallback.GetDatatableECM(oSQL)
             CURRENT_DOC_ID = 0
             CURRENT_DOC_GUID = 0
@@ -3808,7 +3814,7 @@ Public Class frmValidator
                     oNewGUID = oDT.Rows(0).Item(0)
                     MyValidationLogger.Info($"Get_Next_GUID: oNewGUID [{oNewGUID}]...")
                 Catch ex As Exception
-                    MyValidationLogger.Warn($"⚠️ >> Attention: in GetNextGUID - Could not get the next GUID - SQL [{oSQL}]")
+                    MyValidationLogger.Warn($"⚠️ Attention: in GetNextGUID - Could not get the next GUID - SQL [{oSQL}]")
                     MyValidationLogger.Warn($"⚠️ ERRORMESSAGE [{ex.Message}]")
                 End Try
 
@@ -4053,7 +4059,9 @@ Public Class frmValidator
             MyValidationLogger.Info($"LOG_HOTSPOTS - CURRENT_DOC_GUID: {CURRENT_DOC_GUID}")
             ' ========== ENDE DIAGNOSE ==========
         End If
-
+        ' State-Variablen zurücksetzen beim Laden eines neuen Dokuments
+        previousLUSelectedValues = Nothing
+        hadPreviousLUSelection = False
         Dim oMilliseconts As Double
         clsPatterns.ClearControlCache()  ' Cache-Invalidierung
         Dim perfStart As DateTime = DateTime.MinValue
@@ -5649,16 +5657,14 @@ Public Class frmValidator
                                 Dim oLookup As LookupControl3 = oControl
                                 Dim oLookupMeta As ClassControlCreator.ControlMetadata = DirectCast(oLookup.Tag, ClassControlCreator.ControlMetadata)
 
-                                ' ========== BUGFIX START: Alte SelectedValues SICHERN bevor DataSource überschrieben wird ==========
+                                ' Nur sichern wenn NICHT bereits von einem vorherigen Dokument vorhanden
-                                Dim previousSelectedValues As List(Of String) = Nothing
+                                If Not hadPreviousLUSelection Then
-                                Dim hadPreviousSelection As Boolean = False
+                                    If oLookup.Properties.SelectedValues IsNot Nothing AndAlso oLookup.Properties.SelectedValues.Count > 0 Then
-
+                                        previousLUSelectedValues = New List(Of String)(oLookup.Properties.SelectedValues)
-                                If oLookup.Properties.SelectedValues IsNot Nothing AndAlso oLookup.Properties.SelectedValues.Count > 0 Then
+                                        hadPreviousLUSelection = True
-                                    previousSelectedValues = New List(Of String)(oLookup.Properties.SelectedValues)
+                                        MyValidationLogger.Debug($"[FillIndexValues BUGFIX] Lookup [{oLookupMeta.Name}]: Alte SelectedValues gesichert = [{String.Join(",", previousLUSelectedValues)}]")
-                                    hadPreviousSelection = True
+                                    End If
-                                    MyValidationLogger.Debug($"[FillIndexValues BUGFIX] Lookup [{oLookupMeta.Name}]: Alte SelectedValues gesichert = [{String.Join(",", previousSelectedValues)}]")
                                 End If
-                                ' ========== BUGFIX END: Sicherung ==========
 
                                 oValueFromSource = GetVariableValuefromSource(oSourceIndexName, oIDBTyp, oIDBOverride)
 
@@ -5691,20 +5697,20 @@ Public Class frmValidator
                                     End If
                                 Else
                                     ' ========== BUGFIX START: Wenn KEIN neuer Wert, alte Werte behalten ==========
-                                    If hadPreviousSelection AndAlso previousSelectedValues IsNot Nothing AndAlso previousSelectedValues.Count > 0 Then
+                                    If hadPreviousLUSelection AndAlso previousLUSelectedValues IsNot Nothing AndAlso previousLUSelectedValues.Count > 0 Then
                                         MyValidationLogger.Debug($"[FillIndexValues BUGFIX] Lookup [{oLookupMeta.Name}]: Kein neuer Wert von Quelle → alte Werte BEHALTEN")
-                                        oNewValues = previousSelectedValues
+                                        oNewValues = previousLUSelectedValues
                                     ElseIf oDefaultValue <> String.Empty Then
-                                        MyValidationLogger.Debug($"[FillIndexValues BUGFIX] Lookup [{oLookupMeta.Name}]: Keine alten Werte, verwende DefaultValue = [{oDefaultValue}]")
+                                        MyValidationLogger.Debug($"[FillIndexValues BUGFIX] Lookup [{oLookupMeta.Name}]: Verwende DefaultValue = [{oDefaultValue}]")
                                         oNewValues = oDefaultValue.Split(",").ToList()
                                     Else
-                                        MyValidationLogger.Debug($"[FillIndexValues BUGFIX] Lookup [{oLookupMeta.Name}]: KEINE Werte (oValueFromSource=Nothing, oDefaultValue leer, keine vorherigen Werte)")
+                                        MyValidationLogger.Debug($"[FillIndexValues BUGFIX] Lookup [{oLookupMeta.Name}]: KEINE Werte!")
                                     End If
-                                    ' ========== BUGFIX END: Wert-Beibehaltung ==========
+                                        ' ========== BUGFIX END: Wert-Beibehaltung ==========
-                                End If
+                                   End If
 
-                                ' ========== KRITISCH: DataSource-Backup erstellen BEVOR SelectedValues gelöscht wird ==========
+                                    ' ========== KRITISCH: DataSource-Backup erstellen BEVOR SelectedValues gelöscht wird ==========
-                                Dim savedDataSource = oLookup.Properties.DataSource
+                                    Dim savedDataSource = oLookup.Properties.DataSource
                                 MyValidationLogger.Debug($"[FillIndexValues BUGFIX] Lookup [{oLookupMeta.Name}]: DataSource-Backup erstellt")
 
                                 ' ========== KRITISCH: DataSource ZUERST wiederherstellen, DANN SelectedValues leeren ==========
@@ -8508,8 +8514,9 @@ Public Class frmValidator
         Cursor = Cursors.WaitCursor
         Dim perfStart As DateTime = If(LOG_HOTSPOTS, DateTime.Now, Nothing)
         Dim perfLastCheck As DateTime = perfStart
-
+        ' ========== WICHTIG: State-Variablen zurücksetzen vor neuem Dokument ==========
-
+        previousLUSelectedValues = Nothing
+        hadPreviousLUSelection = False
 
         If LOG_HOTSPOTS Then
             ' ========== DIAGNOSE START ==========
@@ -8531,12 +8538,7 @@ Public Class frmValidator
                 ' ========== ENDE DIAGNOSE ==========
 
             End If
-
-
             Reset_CurrentReferences()
-
-
-
             If LOG_HOTSPOTS Then
                 MyValidationLogger.Info($"[PERF] Nach Reset_CurrentReferences: {(DateTime.Now - perfLastCheck).TotalMilliseconds}ms")
                 perfLastCheck = DateTime.Now