Index: Ringtoets/Integration/src/Ringtoets.Integration.Forms/PropertyClasses/HydraulicBoundaryDatabaseProperties.cs
===================================================================
diff -u -rac96d7c315129af851634ed5a4a6800b59ede718 -rc596452c5be18e76aea44c66f5b947e8088eacff
--- Ringtoets/Integration/src/Ringtoets.Integration.Forms/PropertyClasses/HydraulicBoundaryDatabaseProperties.cs	(.../HydraulicBoundaryDatabaseProperties.cs)	(revision ac96d7c315129af851634ed5a4a6800b59ede718)
+++ Ringtoets/Integration/src/Ringtoets.Integration.Forms/PropertyClasses/HydraulicBoundaryDatabaseProperties.cs	(.../HydraulicBoundaryDatabaseProperties.cs)	(revision c596452c5be18e76aea44c66f5b947e8088eacff)
@@ -80,12 +80,12 @@
             set
             {
                 data.WrappedData.HydraulicBoundaryDatabase.UsePreprocessor = value;
+                data.WrappedData.NotifyObservers();
             }
         }
 
         [PropertyOrder(3)]
         [DynamicVisible]
-        [DynamicReadOnly]
         [ResourcesCategory(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.Categories_General))]
         [ResourcesDisplayName(typeof(Resources), nameof(Resources.HydraulicBoundaryDatabase_PreprocessorDirectory_DisplayName))]
         [ResourcesDescription(typeof(Resources), nameof(Resources.HydraulicBoundaryDatabase_PreprocessorDirectory_Description))]
@@ -102,24 +102,40 @@
             }
         }
 
-        [DynamicVisibleValidationMethod]
-        public bool DynamicVisibleValidationMethod(string propertyName)
+        [PropertyOrder(4)]
+        [DynamicVisible]
+        [ResourcesCategory(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.Categories_General))]
+        [ResourcesDisplayName(typeof(Resources), nameof(Resources.HydraulicBoundaryDatabase_PreprocessorDirectory_DisplayName))]
+        [ResourcesDescription(typeof(Resources), nameof(Resources.HydraulicBoundaryDatabase_PreprocessorDirectory_Description))]
+        public string PreprocessorDirectoryReadOnly
         {
-            if (propertyName.Equals(nameof(UsePreprocessor)) || propertyName.Equals(nameof(PreprocessorDirectory)))
+            get
             {
-                return data.WrappedData.HydraulicBoundaryDatabase?.CanUsePreprocessor ?? false;
+                return data.WrappedData.HydraulicBoundaryDatabase.PreprocessorDirectory;
             }
-            return true;
         }
 
-        [DynamicReadOnlyValidationMethod]
-        public bool DynamicReadOnlyValidationMethod(string propertyName)
+        [DynamicVisibleValidationMethod]
+        public bool DynamicVisibleValidationMethod(string propertyName)
         {
-            if (propertyName.Equals(nameof(PreprocessorDirectory)))
+            bool canUsePreprocessor = data.WrappedData.HydraulicBoundaryDatabase?.CanUsePreprocessor ?? false;
+
+            if (propertyName.Equals(nameof(UsePreprocessor)) && !canUsePreprocessor)
             {
-                return !data.WrappedData.HydraulicBoundaryDatabase.UsePreprocessor;
+                return false;
             }
-            return false;
+
+            if (propertyName.Equals(nameof(PreprocessorDirectory)) && (!canUsePreprocessor || !UsePreprocessor))
+            {
+                return false;
+            }
+
+            if (propertyName.Equals(nameof(PreprocessorDirectoryReadOnly)) && (!canUsePreprocessor || UsePreprocessor))
+            {
+                return false;
+            }
+
+            return true;
         }
     }
 }
\ No newline at end of file
Index: Ringtoets/Integration/test/Ringtoets.Integration.Forms.Test/PropertyClasses/HydraulicBoundaryDatabasePropertiesTest.cs
===================================================================
diff -u -r73162f4fb6fd9caae7e48d464eab43510c70f52b -rc596452c5be18e76aea44c66f5b947e8088eacff
--- Ringtoets/Integration/test/Ringtoets.Integration.Forms.Test/PropertyClasses/HydraulicBoundaryDatabasePropertiesTest.cs	(.../HydraulicBoundaryDatabasePropertiesTest.cs)	(revision 73162f4fb6fd9caae7e48d464eab43510c70f52b)
+++ Ringtoets/Integration/test/Ringtoets.Integration.Forms.Test/PropertyClasses/HydraulicBoundaryDatabasePropertiesTest.cs	(.../HydraulicBoundaryDatabasePropertiesTest.cs)	(revision c596452c5be18e76aea44c66f5b947e8088eacff)
@@ -20,9 +20,11 @@
 // All rights reserved.
 
 using System.ComponentModel;
+using Core.Common.Base;
 using Core.Common.Gui.PropertyBag;
 using Core.Common.TestUtil;
 using NUnit.Framework;
+using Rhino.Mocks;
 using Ringtoets.Common.Data.AssessmentSection;
 using Ringtoets.Common.Data.Hydraulics;
 using Ringtoets.Integration.Data;
@@ -82,6 +84,7 @@
             Assert.AreEqual(filePath, properties.FilePath);
             Assert.AreEqual(usePreprocessor, properties.UsePreprocessor);
             Assert.AreEqual(preprocessorDirectory, properties.PreprocessorDirectory);
+            Assert.AreEqual(preprocessorDirectory, properties.PreprocessorDirectoryReadOnly);
         }
 
         [Test]
@@ -180,16 +183,24 @@
         }
 
         [Test]
-        public void UsePreprocessor_SetNewValue_ValueSetToHydraulicBoundaryDataBase([Values(true, false)] bool usePreprocessor)
+        public void UsePreprocessor_SetNewValue_ValueSetToHydraulicBoundaryDatabaseAndObserversNotified([Values(true, false)] bool usePreprocessor)
         {
             // Setup
+            var mocks = new MockRepository();
+            var observer = mocks.StrictMock<IObserver>();
+
+            observer.Expect(o => o.UpdateObserver());
+
+            mocks.ReplayAll();
+
             var hydraulicBoundaryDatabase = new HydraulicBoundaryDatabase
             {
                 CanUsePreprocessor = true,
                 UsePreprocessor = !usePreprocessor,
                 PreprocessorDirectory = "Preprocessor"
             };
-            var context = new HydraulicBoundaryDatabaseContext(new AssessmentSection(AssessmentSectionComposition.Dike))
+            var assessmentSection = new AssessmentSection(AssessmentSectionComposition.Dike);
+            var context = new HydraulicBoundaryDatabaseContext(assessmentSection)
             {
                 WrappedData =
                 {
@@ -198,15 +209,18 @@
             };
             var properties = new HydraulicBoundaryDatabaseProperties(context);
 
+            assessmentSection.Attach(observer);
+
             // Call
             properties.UsePreprocessor = usePreprocessor;
 
             // Assert
             Assert.AreEqual(usePreprocessor, hydraulicBoundaryDatabase.UsePreprocessor);
+            mocks.VerifyAll();
         }
 
         [Test]
-        public void PreprocessorDirectory_SetNewValue_ValueSetToHydraulicBoundaryDataBase()
+        public void PreprocessorDirectory_SetNewValue_ValueSetToHydraulicBoundaryDatabase()
         {
             // Setup
             const string newPreprocessorDirectory = @"C:/path";
@@ -233,17 +247,17 @@
         }
 
         [Test]
-        [TestCase(true)]
-        [TestCase(false)]
-        public void DynamicVisibleValidationMethod_DependingOnCanUsePreprocessor_ReturnExpectedVisibility(bool canUsePreprocessor)
+        public void DynamicVisibleValidationMethod_DependingOnCanUsePreprocessorAndUsePreprocessor_ReturnExpectedVisibility(
+            [Values(true, false)] bool canUsePreprocessor,
+            [Values(true, false)] bool usePreprocessor)
         {
             // Setup
             var hydraulicBoundaryDatabase = new HydraulicBoundaryDatabase();
 
             if (canUsePreprocessor)
             {
                 hydraulicBoundaryDatabase.CanUsePreprocessor = true;
-                hydraulicBoundaryDatabase.UsePreprocessor = true;
+                hydraulicBoundaryDatabase.UsePreprocessor = usePreprocessor;
                 hydraulicBoundaryDatabase.PreprocessorDirectory = "Preprocessor";
             }
 
@@ -256,9 +270,10 @@
             var properties = new HydraulicBoundaryDatabaseProperties(context);
 
             // Assert
-            Assert.AreEqual(canUsePreprocessor, properties.DynamicVisibleValidationMethod(nameof(properties.UsePreprocessor)));
-            Assert.AreEqual(canUsePreprocessor, properties.DynamicVisibleValidationMethod(nameof(properties.PreprocessorDirectory)));
             Assert.IsTrue(properties.DynamicVisibleValidationMethod(nameof(properties.FilePath)));
+            Assert.AreEqual(canUsePreprocessor, properties.DynamicVisibleValidationMethod(nameof(properties.UsePreprocessor)));
+            Assert.AreEqual(canUsePreprocessor && usePreprocessor, properties.DynamicVisibleValidationMethod(nameof(properties.PreprocessorDirectory)));
+            Assert.AreEqual(canUsePreprocessor && !usePreprocessor, properties.DynamicVisibleValidationMethod(nameof(properties.PreprocessorDirectoryReadOnly)));
         }
 
         [Test]
@@ -271,33 +286,10 @@
             var properties = new HydraulicBoundaryDatabaseProperties(context);
 
             // Assert
+            Assert.IsTrue(properties.DynamicVisibleValidationMethod(nameof(properties.FilePath)));
             Assert.IsFalse(properties.DynamicVisibleValidationMethod(nameof(properties.UsePreprocessor)));
             Assert.IsFalse(properties.DynamicVisibleValidationMethod(nameof(properties.PreprocessorDirectory)));
-            Assert.IsTrue(properties.DynamicVisibleValidationMethod(nameof(properties.FilePath)));
+            Assert.IsFalse(properties.DynamicVisibleValidationMethod(nameof(properties.PreprocessorDirectoryReadOnly)));
         }
-
-        [Test]
-        [TestCase(true)]
-        [TestCase(false)]
-        public void DynamicReadOnlyValidationMethod_DependingOnUsePreprocessor_ReturnExpectedValue(bool usePreprocessor)
-        {
-            // Setup
-            var context = new HydraulicBoundaryDatabaseContext(new AssessmentSection(AssessmentSectionComposition.Dike)
-            {
-                HydraulicBoundaryDatabase = new HydraulicBoundaryDatabase
-                {
-                    CanUsePreprocessor = true,
-                    UsePreprocessor = usePreprocessor,
-                    PreprocessorDirectory = "Preprocessor"
-                }
-            });
-
-            // Call
-            var properties = new HydraulicBoundaryDatabaseProperties(context);
-
-            // Assert
-            Assert.AreEqual(!usePreprocessor, properties.DynamicReadOnlyValidationMethod(nameof(properties.PreprocessorDirectory)));
-            Assert.IsFalse(properties.DynamicReadOnlyValidationMethod(nameof(properties.UsePreprocessor)));
-        }
     }
 }
\ No newline at end of file