Index: Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Service/HeightStructuresCalculationService.cs
===================================================================
diff -u -rf4f041e353f89e0e93a4243968acee599b2186a7 -rffe6f47c5c38e57f5c0c0d9c699c88ac6c818e7c
--- Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Service/HeightStructuresCalculationService.cs	(.../HeightStructuresCalculationService.cs)	(revision f4f041e353f89e0e93a4243968acee599b2186a7)
+++ Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Service/HeightStructuresCalculationService.cs	(.../HeightStructuresCalculationService.cs)	(revision ffe6f47c5c38e57f5c0c0d9c699c88ac6c818e7c)
@@ -19,9 +19,11 @@
 // Stichting Deltares and remain full property of Stichting Deltares at all times.
 // All rights reserved.
 
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using Core.Common.IO.Exceptions;
 using log4net;
 using Ringtoets.Common.Data.AssessmentSection;
 using Ringtoets.Common.Data.FailureMechanism;
@@ -38,7 +40,6 @@
 using Ringtoets.HydraRing.Calculation.Data.Input.Structures;
 using Ringtoets.HydraRing.Calculation.Exceptions;
 using RingtoetsCommonServiceResources = Ringtoets.Common.Service.Properties.Resources;
-using RingtoetsCommonDataResources = Ringtoets.Common.Data.Properties.Resources;
 using RingtoetsCommonFormsResources = Ringtoets.Common.Forms.Properties.Resources;
 
 namespace Ringtoets.HeightStructures.Service
@@ -60,8 +61,17 @@
         /// <param name="calculation">The <see cref="StructuresCalculation{T}"/> for which to validate the values.</param>
         /// <param name="assessmentSection">The <see cref="IAssessmentSection"/> for which to validate the values.</param>
         /// <returns><c>True</c> if <paramref name="calculation"/> has no validation errors; <c>False</c> otherwise.</returns>
+        /// <exception cref="ArgumentNullException">Thrown when any parameter is <c>null</c>.</exception>
         public static bool Validate(StructuresCalculation<HeightStructuresInput> calculation, IAssessmentSection assessmentSection)
         {
+            if (calculation == null)
+            {
+                throw new ArgumentNullException(nameof(calculation));
+            }
+            if (assessmentSection == null)
+            {
+                throw new ArgumentNullException(nameof(assessmentSection));
+            }
             CalculationServiceHelper.LogValidationBeginTime(calculation.Name);
 
             string[] messages = ValidateInput(calculation.InputParameters, assessmentSection);
@@ -77,10 +87,7 @@
         /// </summary>
         public void Cancel()
         {
-            if (calculator != null)
-            {
-                calculator.Cancel();
-            }
+            calculator?.Cancel();
             canceled = true;
         }
 
@@ -93,13 +100,38 @@
         /// <param name="failureMechanism"> The <see cref="HeightStructuresFailureMechanism"/> that holds the information about the contribution 
         /// and the general inputs used in the calculation.</param>
         /// <param name="hydraulicBoundaryDatabaseFilePath">The path which points to the hydraulic boundary database file.</param>
+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="calculation"/>, <paramref name="assessmentSection"/>
+        /// or <paramref name="failureMechanism"/> is <c>null</c>.</exception>
+        /// <exception cref="ArgumentException">Thrown when the <paramref name="hydraulicBoundaryDatabaseFilePath"/> 
+        /// contains invalid characters.</exception>
+        /// <exception cref="CriticalFileReadException">Thrown when:
+        /// <list type="bullet">
+        /// <item>No settings database file could be found at the location of <paramref name="hydraulicBoundaryDatabaseFilePath"/>
+        /// with the same name.</item>
+        /// <item>Unable to open settings database file.</item>
+        /// <item>Unable to read required data from database file.</item>
+        /// </list>
+        /// </exception>
         /// <exception cref="HydraRingFileParserException">Thrown when an error occurs during parsing of the Hydra-Ring output.</exception>
         /// <exception cref="HydraRingCalculationException">Thrown when an error occurs during the calculation.</exception>
         internal void Calculate(StructuresCalculation<HeightStructuresInput> calculation,
                                 IAssessmentSection assessmentSection,
                                 HeightStructuresFailureMechanism failureMechanism,
                                 string hydraulicBoundaryDatabaseFilePath)
         {
+            if (calculation == null)
+            {
+                throw new ArgumentNullException(nameof(calculation));
+            }
+            if (assessmentSection == null)
+            {
+                throw new ArgumentNullException(nameof(assessmentSection));
+            }
+            if (failureMechanism == null)
+            {
+                throw new ArgumentNullException(nameof(failureMechanism));
+            }
+
             var calculationName = calculation.Name;
 
             FailureMechanismSection failureMechanismSection = StructuresHelper.FailureMechanismSectionForCalculation(failureMechanism.Sections,
@@ -166,6 +198,24 @@
             }
         }
 
+        /// <summary>
+        /// Creates the input for a structures overtopping calculation.
+        /// </summary>
+        /// <param name="calculation">The calculation to create the input for.</param>
+        /// <param name="failureMechanismSection">The failure mechanism section to use in the calculation.</param>
+        /// <param name="generalInput">The general input to use in the calculation.</param>
+        /// <param name="hydraulicBoundaryDatabaseFilePath">The path to the hydraulic boundary database file.</param>
+        /// <returns>A <see cref="StructuresOvertoppingCalculationInput"/>.</returns>
+        /// <exception cref="ArgumentException">Thrown when the <paramref name="hydraulicBoundaryDatabaseFilePath"/> 
+        /// contains invalid characters.</exception>
+        /// <exception cref="CriticalFileReadException">Thrown when:
+        /// <list type="bullet">
+        /// <item>No settings database file could be found at the location of <paramref name="hydraulicBoundaryDatabaseFilePath"/>
+        /// with the same name.</item>
+        /// <item>Unable to open settings database file.</item>
+        /// <item>Unable to read required data from database file.</item>
+        /// </list>
+        /// </exception>
         private static StructuresOvertoppingCalculationInput CreateInput(
             StructuresCalculation<HeightStructuresInput> calculation,
             FailureMechanismSection failureMechanismSection,