Index: Core/Common/test/Core.Common.TestUtil/LogLevelConstant.cs
===================================================================
diff -u -r7f82fd637dc8796f3d270cb0fa6d9ab18548c6f4 -rffba5900acc192187346a9ad73acea5e8b9d0bf5
--- Core/Common/test/Core.Common.TestUtil/LogLevelConstant.cs	(.../LogLevelConstant.cs)	(revision 7f82fd637dc8796f3d270cb0fa6d9ab18548c6f4)
+++ Core/Common/test/Core.Common.TestUtil/LogLevelConstant.cs	(.../LogLevelConstant.cs)	(revision ffba5900acc192187346a9ad73acea5e8b9d0bf5)
@@ -35,6 +35,9 @@
         Debug
     }
 
+    /// <summary>
+    /// Extension methods for the <see cref="LogLevelConstant"/>.
+    /// </summary>
     public static class LogLevelConstantExtensions
     {
         /// <summary>
Index: Ringtoets/Integration/src/Ringtoets.Integration.Plugin/RingtoetsPlugin.cs
===================================================================
diff -u -r16559315c0a64fffd05827d249200c62e353231f -rffba5900acc192187346a9ad73acea5e8b9d0bf5
--- Ringtoets/Integration/src/Ringtoets.Integration.Plugin/RingtoetsPlugin.cs	(.../RingtoetsPlugin.cs)	(revision 16559315c0a64fffd05827d249200c62e353231f)
+++ Ringtoets/Integration/src/Ringtoets.Integration.Plugin/RingtoetsPlugin.cs	(.../RingtoetsPlugin.cs)	(revision ffba5900acc192187346a9ad73acea5e8b9d0bf5)
@@ -1331,8 +1331,24 @@
 
         #region CategoryTreeFolder TreeNodeInfo
 
+        /// <summary>
+        /// Gets an <see cref="Image"/> based on <paramref name="category"/>.
+        /// </summary>
+        /// <param name="category">The tree folder category to retrieve the image for.</param>
+        /// <returns>An <see cref="Image"/> based on <paramref name="category"/>.</returns>
+        /// <exception cref="InvalidEnumArgumentException">Thrown when <paramref name="category"/>
+        /// is an invalid value of <see cref="TreeFolderCategory"/>.</exception>
+        /// <exception cref="NotSupportedException">Thrown when <paramref name="category"/>
+        /// is an unsupported value of <see cref="TreeFolderCategory"/>.</exception>
         private static Image GetFolderIcon(TreeFolderCategory category)
         {
+            if (!Enum.IsDefined(typeof(TreeFolderCategory), category))
+            {
+                throw new InvalidEnumArgumentException(nameof(category),
+                                                       (int) category,
+                                                       typeof(TreeFolderCategory));
+            }
+
             switch (category)
             {
                 case TreeFolderCategory.General:
@@ -1342,9 +1358,7 @@
                 case TreeFolderCategory.Output:
                     return RingtoetsCommonFormsResources.OutputFolderIcon;
                 default:
-                    throw new InvalidEnumArgumentException(nameof(category),
-                                                           (int) category,
-                                                           typeof(TreeFolderCategory));
+                    throw new NotSupportedException($"The enum value {nameof(TreeFolderCategory)}.{category} is not supported.");
             }
         }
 
Index: Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.Data/MacroStabilityInwardsFailureMechanismSection2aAssessmentResultExtensions.cs
===================================================================
diff -u -r00da0d2f72214f140bceff0eaae5f14172c587de -rffba5900acc192187346a9ad73acea5e8b9d0bf5
--- Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.Data/MacroStabilityInwardsFailureMechanismSection2aAssessmentResultExtensions.cs	(.../MacroStabilityInwardsFailureMechanismSection2aAssessmentResultExtensions.cs)	(revision 00da0d2f72214f140bceff0eaae5f14172c587de)
+++ Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.Data/MacroStabilityInwardsFailureMechanismSection2aAssessmentResultExtensions.cs	(.../MacroStabilityInwardsFailureMechanismSection2aAssessmentResultExtensions.cs)	(revision ffba5900acc192187346a9ad73acea5e8b9d0bf5)
@@ -19,6 +19,7 @@
 // Stichting Deltares and remain full property of Stichting Deltares at all times.
 // All rights reserved.
 
+using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
@@ -85,6 +86,7 @@
         /// <param name="calculations">All calculations in the failure mechanism.</param>
         /// <exception cref="InvalidEnumArgumentException">Thrown when any of the relevant calculations 
         /// in <paramref name="macroStabilityInwardsFailureMechanismSectionResult"/> has an invalid <see cref="CalculationScenarioStatus"/>.</exception>
+        /// <exception cref="NotSupportedException">Thrown when any of the relevant scenarios has an unsupported value of <see cref="CalculationScenarioStatus"/>.</exception>
         public static CalculationScenarioStatus GetCalculationScenarioStatus(
             this MacroStabilityInwardsFailureMechanismSectionResult macroStabilityInwardsFailureMechanismSectionResult,
             IEnumerable<MacroStabilityInwardsCalculationScenario> calculations)
@@ -93,6 +95,14 @@
             var notCalculated = false;
             foreach (MacroStabilityInwardsCalculationScenario calculationScenario in macroStabilityInwardsFailureMechanismSectionResult.GetCalculationScenarios(calculations).Where(cs => cs.IsRelevant))
             {
+                CalculationScenarioStatus calculationScenarioStatus = calculationScenario.Status;
+                if (!Enum.IsDefined(typeof(CalculationScenarioStatus), calculationScenarioStatus))
+                {
+                    throw new InvalidEnumArgumentException(nameof(macroStabilityInwardsFailureMechanismSectionResult),
+                                                           (int)calculationScenarioStatus,
+                                                           typeof(CalculationScenarioStatus));
+                }
+
                 switch (calculationScenario.Status)
                 {
                     case CalculationScenarioStatus.Failed:
@@ -104,9 +114,7 @@
                     case CalculationScenarioStatus.Done:
                         continue;
                     default:
-                        throw new InvalidEnumArgumentException(nameof(macroStabilityInwardsFailureMechanismSectionResult),
-                                                               (int) calculationScenario.Status,
-                                                               typeof(CalculationScenarioStatus));
+                        throw new NotSupportedException($"The enum value {nameof(CalculationScenarioStatus)}.{calculationScenarioStatus} is not supported.");
                 }
             }
 
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/PipingFailureMechanismSection2aAssessmentResultExtensions.cs
===================================================================
diff -u -r00da0d2f72214f140bceff0eaae5f14172c587de -rffba5900acc192187346a9ad73acea5e8b9d0bf5
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/PipingFailureMechanismSection2aAssessmentResultExtensions.cs	(.../PipingFailureMechanismSection2aAssessmentResultExtensions.cs)	(revision 00da0d2f72214f140bceff0eaae5f14172c587de)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/PipingFailureMechanismSection2aAssessmentResultExtensions.cs	(.../PipingFailureMechanismSection2aAssessmentResultExtensions.cs)	(revision ffba5900acc192187346a9ad73acea5e8b9d0bf5)
@@ -19,6 +19,7 @@
 // Stichting Deltares and remain full property of Stichting Deltares at all times.
 // All rights reserved.
 
+using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
@@ -85,15 +86,24 @@
         /// <param name="calculations">All calculations in the failure mechanism.</param>
         /// <exception cref="InvalidEnumArgumentException">Thrown when any of the relevant calculations 
         /// in <paramref name="pipingFailureMechanismSectionResult"/> has an invalid <see cref="CalculationScenarioStatus"/>.</exception>
+        /// <exception cref="NotSupportedException">Thrown when any of the relevant scenarios has an unsupported value of <see cref="CalculationScenarioStatus"/>.</exception>
         public static CalculationScenarioStatus GetCalculationScenarioStatus(this PipingFailureMechanismSectionResult pipingFailureMechanismSectionResult,
                                                                              IEnumerable<PipingCalculationScenario> calculations)
         {
             var failed = false;
             var notCalculated = false;
             foreach (PipingCalculationScenario calculationScenario in pipingFailureMechanismSectionResult.GetCalculationScenarios(calculations).Where(cs => cs.IsRelevant))
             {
-                switch (calculationScenario.Status)
+                CalculationScenarioStatus calculationScenarioStatus = calculationScenario.Status;
+                if (!Enum.IsDefined(typeof(CalculationScenarioStatus), calculationScenarioStatus))
                 {
+                    throw new InvalidEnumArgumentException(nameof(pipingFailureMechanismSectionResult),
+                                                           (int)calculationScenarioStatus,
+                                                           typeof(CalculationScenarioStatus));
+                }
+
+                switch (calculationScenarioStatus)
+                {
                     case CalculationScenarioStatus.Failed:
                         failed = true;
                         break;
@@ -103,9 +113,7 @@
                     case CalculationScenarioStatus.Done:
                         continue;
                     default:
-                        throw new InvalidEnumArgumentException(nameof(pipingFailureMechanismSectionResult),
-                                                               (int) calculationScenario.Status,
-                                                               typeof(CalculationScenarioStatus));
+                       throw new NotSupportedException($"The enum value {nameof(CalculationScenarioStatus)}.{calculationScenarioStatus} is not supported.");
                 }
             }