diff --git a/app/DD_PM_WINDREAM/ClassControlCreator.vb b/app/DD_PM_WINDREAM/ClassControlCreator.vb
index 4f58ac0..2e56dc8 100644
--- a/app/DD_PM_WINDREAM/ClassControlCreator.vb
+++ b/app/DD_PM_WINDREAM/ClassControlCreator.vb
@@ -116,7 +116,8 @@ Public Class ClassControlCreator
             .AutoSize = True,
             .Text = DEFAULT_TEXT,
             .Cursor = Cursors.Hand,
-            .Location = location
+            .Location = location,
+            .CheckState = CheckState.Indeterminate
         }
 
         Return control
@@ -278,6 +279,7 @@ Public Class ClassControlCreator
 
         control.AutoSize = True
         control.Text = row.Item("CTRL_TEXT")
+        control.CheckState = CheckState.Indeterminate
 
         If Not designMode Then
             control.Enabled = Not row.Item("READ_ONLY")
diff --git a/app/DD_PM_WINDREAM/frmMassValidator.vb b/app/DD_PM_WINDREAM/frmMassValidator.vb
index 66775fb..63fd648 100644
--- a/app/DD_PM_WINDREAM/frmMassValidator.vb
+++ b/app/DD_PM_WINDREAM/frmMassValidator.vb
@@ -1543,12 +1543,16 @@ Public Class frmMassValidator
                             Dim chk As CheckBox = oControl
                             oMyControlInput = chk.Checked.ToString
 
-                            If chk.Checked = False And _MUSSEINGABE = True Then
+                            If chk.CheckState = CheckState.Indeterminate And _MUSSEINGABE = True Then
                                 oMissing = True
                                 oErrorMessage = "Option '" & chk.Name & "' is required."
                                 Exit For
                             End If
 
+                            If chk.CheckState = CheckState.Indeterminate Then
+                                LOGGER.Debug("Checkbox {0} is indeterminate. Skipping indexing.", chk.Name)
+                                Exit For
+                            End If
 
                             Dim result() As String
                             ReDim Preserve result(0)