Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/DikesDesign/DesignCalculatorSingle.cs
===================================================================
diff -u -r7002 -r7077
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/DikesDesign/DesignCalculatorSingle.cs	(.../DesignCalculatorSingle.cs)	(revision 7002)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/DikesDesign/DesignCalculatorSingle.cs	(.../DesignCalculatorSingle.cs)	(revision 7077)
@@ -1,4 +1,4 @@
-// Copyright (C) Stichting Deltares 2025. All rights reserved.
+// Copyright (C) Stichting Deltares 2026. All rights reserved.
 // 
 // This file is part of the Dam Engine.
 // 
@@ -66,15 +66,16 @@
                 var validationStringBuilder = new StringBuilder();
                 if (validationMessages != null && validationMessages.Count > 0)
                 {
-                    foreach (var validationMessage in validationMessages)
+                    foreach (LogMessage validationMessage in validationMessages)
                     {
                         validationStringBuilder.AppendLine(validationMessage.Message);
                     }
                 }
+
                 string message = string.Format(Resources.DesignCalculatorValidationFailed,
                                                damKernelInput.Location.Name,
                                                damKernelInput.SubSoilScenario,
-                                               designScenario.LocationScenarioID) + validationStringBuilder.ToString();
+                                               designScenario.LocationScenarioID) + validationStringBuilder;
                 locationCalculationMessages.Add(new LogMessage(LogMessageType.Error, null, message));
             }
             else