Index: Riskeer/Piping/src/Riskeer.Piping.Service/Probabilistic/ProbabilisticPipingCalculationService.cs
===================================================================
diff -u -r44472a4abdebe721072cb648140d9254bc25bd1a -r2d896c48d4bb6a88b80b6bfb3146ee14737b2921
--- Riskeer/Piping/src/Riskeer.Piping.Service/Probabilistic/ProbabilisticPipingCalculationService.cs	(.../ProbabilisticPipingCalculationService.cs)	(revision 44472a4abdebe721072cb648140d9254bc25bd1a)
+++ Riskeer/Piping/src/Riskeer.Piping.Service/Probabilistic/ProbabilisticPipingCalculationService.cs	(.../ProbabilisticPipingCalculationService.cs)	(revision 2d896c48d4bb6a88b80b6bfb3146ee14737b2921)
@@ -27,7 +27,6 @@
 using log4net;
 using Riskeer.Common.Data.AssessmentSection;
 using Riskeer.Common.Data.Exceptions;
-using Riskeer.Common.Data.FailureMechanism;
 using Riskeer.Common.Data.Hydraulics;
 using Riskeer.Common.Data.IllustrationPoints;
 using Riskeer.Common.Data.Probabilistics;
@@ -82,14 +81,14 @@
                 throw new ArgumentNullException(nameof(calculation));
             }
 
-            if (assessmentSection == null)
+            if (failureMechanism == null)
             {
-                throw new ArgumentNullException(nameof(assessmentSection));
+                throw new ArgumentNullException(nameof(failureMechanism));
             }
 
-            if (failureMechanism == null)
+            if (assessmentSection == null)
             {
-                throw new ArgumentNullException(nameof(failureMechanism));
+                throw new ArgumentNullException(nameof(assessmentSection));
             }
 
             CalculationServiceHelper.LogValidationBegin();
@@ -453,30 +452,21 @@
         {
             string[] messages = ValidateHydraulicBoundaryDatabase(assessmentSection).ToArray();
 
-            if (messages.Length > 0)
+            if (messages.Length == 0)
             {
-                CalculationServiceHelper.LogMessagesAsError(messages);
-                return true;
+                messages = ValidateFailureMechanismHasSections(failureMechanism).ToArray();
             }
 
-            messages = ValidateFailureMechanismHasSections(failureMechanism).ToArray();
-
-            if (messages.Length > 0)
+            if (messages.Length == 0)
             {
-                CalculationServiceHelper.LogMessagesAsError(messages);
-                return true;
+                messages = ValidateInput(calculation.InputParameters, failureMechanism.GeneralInput).ToArray();
             }
 
-            messages = ValidateInput(calculation.InputParameters, failureMechanism.GeneralInput).ToArray();
-
-            if (messages.Length > 0)
+            if (messages.Length == 0)
             {
-                CalculationServiceHelper.LogMessagesAsError(messages);
-                return true;
+                messages = ValidateCalculationInMultipleSections(calculation, failureMechanism).ToArray();
             }
 
-            messages = ValidateCalculationInMultipleSections(calculation, failureMechanism).ToArray();
-
             if (messages.Length > 0)
             {
                 CalculationServiceHelper.LogMessagesAsError(messages);
@@ -486,37 +476,6 @@
             return false;
         }
 
-        private static IEnumerable<string> ValidateFailureMechanismHasSections(PipingFailureMechanism failureMechanism)
-        {
-            var validationResults = new List<string>();
-
-            FailureMechanismSection[] sections = failureMechanism.Sections.ToArray();
-
-            if (sections.Length == 0)
-            {
-                validationResults.Add(Resources.ProbabilisticPipingCalculationService_ValidateSections_No_sections_imported);
-            }
-
-            return validationResults;
-        }
-
-        private static IEnumerable<string> ValidateCalculationInMultipleSections(ProbabilisticPipingCalculation calculation, PipingFailureMechanism failureMechanism)
-        {
-            var validationResults = new List<string>();
-
-            FailureMechanismSection[] sections = failureMechanism
-                                                 .Sections
-                                                 .Where(section => calculation.IsSurfaceLineIntersectionWithReferenceLineInSection(Math2D.ConvertPointsToLineSegments(section.Points)))
-                                                 .ToArray();
-
-            if (sections.Length > 1)
-            {
-                validationResults.Add(Resources.ProbabilisticPipingCalculationService_ValidateSections_Cannot_determine_section_for_calculation);
-            }
-
-            return validationResults;
-        }
-
         private static IEnumerable<string> ValidateHydraulicBoundaryDatabase(IAssessmentSection assessmentSection)
         {
             string preprocessorDirectory = assessmentSection.HydraulicBoundaryDatabase.EffectivePreprocessorDirectory();
@@ -533,6 +492,14 @@
             }
         }
 
+        private static IEnumerable<string> ValidateFailureMechanismHasSections(PipingFailureMechanism failureMechanism)
+        {
+            if (!failureMechanism.Sections.Any())
+            {
+                yield return Resources.ProbabilisticPipingCalculationService_ValidateFailureMechanismHasSections_No_sections_imported;
+            }
+        }
+
         private static IEnumerable<string> ValidateInput(ProbabilisticPipingInput input, GeneralPipingInput generalInput)
         {
             var validationResults = new List<string>();
@@ -564,6 +531,18 @@
             }
         }
 
+        private static IEnumerable<string> ValidateCalculationInMultipleSections(ProbabilisticPipingCalculation calculation, PipingFailureMechanism failureMechanism)
+        {
+            int numberOfSections = failureMechanism
+                                   .Sections
+                                   .Count(section => calculation.IsSurfaceLineIntersectionWithReferenceLineInSection(Math2D.ConvertPointsToLineSegments(section.Points)));
+
+            if (numberOfSections > 1)
+            {
+                yield return Resources.ProbabilisticPipingCalculationService_ValidateCalculationInMultipleSections_Cannot_determine_section_for_calculation;
+            }
+        }
+
         private void NotifyProgress(string stepName, int currentStepNumber, int totalStepNumber)
         {
             OnProgressChanged?.Invoke(stepName, currentStepNumber, totalStepNumber);
Index: Riskeer/Piping/src/Riskeer.Piping.Service/Properties/Resources.Designer.cs
===================================================================
diff -u -r43ea9713b3b60bfb28ec520e5bf807634fffcbf1 -r2d896c48d4bb6a88b80b6bfb3146ee14737b2921
--- Riskeer/Piping/src/Riskeer.Piping.Service/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 43ea9713b3b60bfb28ec520e5bf807634fffcbf1)
+++ Riskeer/Piping/src/Riskeer.Piping.Service/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 2d896c48d4bb6a88b80b6bfb3146ee14737b2921)
@@ -262,31 +262,32 @@
         }
         
         /// <summary>
-        ///   Looks up a localized string similar to De verschuiving van het verzadigd volumetrisch gewicht van de deklaag moet groter zijn dan het volumetrisch gewicht van water..
+        ///   Looks up a localized string similar to Kan geen vak bepalen voor deze berekening: de locatie van de profielschematisatie bevindt zich op de scheiding van twee vakken..
         /// </summary>
-        internal static string ProbabilisticPipingCalculationService_ValidateInput_SaturatedVolumicWeightCoverageLayer_shift_must_be_larger_than_WaterVolumetricWeight {
+        internal static string ProbabilisticPipingCalculationService_ValidateCalculationInMultipleSections_Cannot_determine_section_for_calculation {
             get {
-                return ResourceManager.GetString("ProbabilisticPipingCalculationService_ValidateInput_SaturatedVolumicWeightCoverag" +
-                        "eLayer_shift_must_be_larger_than_WaterVolumetricWeight", resourceCulture);
+                return ResourceManager.GetString("ProbabilisticPipingCalculationService_ValidateCalculationInMultipleSections_Canno" +
+                        "t_determine_section_for_calculation", resourceCulture);
             }
         }
         
         /// <summary>
-        ///   Looks up a localized string similar to Kan geen vak bepalen voor deze berekening: de locatie van de profielschematisatie bevindt zich op de scheiding van twee vakken..
+        ///   Looks up a localized string similar to Er is geen vakindeling geïmporteerd..
         /// </summary>
-        internal static string ProbabilisticPipingCalculationService_ValidateSections_Cannot_determine_section_for_calculation {
+        internal static string ProbabilisticPipingCalculationService_ValidateFailureMechanismHasSections_No_sections_imported {
             get {
-                return ResourceManager.GetString("ProbabilisticPipingCalculationService_ValidateSections_Cannot_determine_section_f" +
-                        "or_calculation", resourceCulture);
+                return ResourceManager.GetString("ProbabilisticPipingCalculationService_ValidateFailureMechanismHasSections_No_sect" +
+                        "ions_imported", resourceCulture);
             }
         }
         
         /// <summary>
-        ///   Looks up a localized string similar to Er is geen vakindeling geïmporteerd..
+        ///   Looks up a localized string similar to De verschuiving van het verzadigd volumetrisch gewicht van de deklaag moet groter zijn dan het volumetrisch gewicht van water..
         /// </summary>
-        internal static string ProbabilisticPipingCalculationService_ValidateSections_No_sections_imported {
+        internal static string ProbabilisticPipingCalculationService_ValidateInput_SaturatedVolumicWeightCoverageLayer_shift_must_be_larger_than_WaterVolumetricWeight {
             get {
-                return ResourceManager.GetString("ProbabilisticPipingCalculationService_ValidateSections_No_sections_imported", resourceCulture);
+                return ResourceManager.GetString("ProbabilisticPipingCalculationService_ValidateInput_SaturatedVolumicWeightCoverag" +
+                        "eLayer_shift_must_be_larger_than_WaterVolumetricWeight", resourceCulture);
             }
         }
         
Index: Riskeer/Piping/src/Riskeer.Piping.Service/Properties/Resources.resx
===================================================================
diff -u -r43ea9713b3b60bfb28ec520e5bf807634fffcbf1 -r2d896c48d4bb6a88b80b6bfb3146ee14737b2921
--- Riskeer/Piping/src/Riskeer.Piping.Service/Properties/Resources.resx	(.../Resources.resx)	(revision 43ea9713b3b60bfb28ec520e5bf807634fffcbf1)
+++ Riskeer/Piping/src/Riskeer.Piping.Service/Properties/Resources.resx	(.../Resources.resx)	(revision 2d896c48d4bb6a88b80b6bfb3146ee14737b2921)
@@ -187,10 +187,10 @@
   <data name="ProbabilisticPipingCalculationService_SectionSpecific" xml:space="preserve">
     <value>vak</value>
   </data>
-  <data name="ProbabilisticPipingCalculationService_ValidateSections_No_sections_imported" xml:space="preserve">
+  <data name="ProbabilisticPipingCalculationService_ValidateFailureMechanismHasSections_No_sections_imported" xml:space="preserve">
     <value>Er is geen vakindeling geïmporteerd.</value>
   </data>
-  <data name="ProbabilisticPipingCalculationService_ValidateSections_Cannot_determine_section_for_calculation" xml:space="preserve">
+  <data name="ProbabilisticPipingCalculationService_ValidateCalculationInMultipleSections_Cannot_determine_section_for_calculation" xml:space="preserve">
     <value>Kan geen vak bepalen voor deze berekening: de locatie van de profielschematisatie bevindt zich op de scheiding van twee vakken.</value>
   </data>
 </root>
\ No newline at end of file