Index: dam engine/trunk/src/Deltares.DamEngine.Interface/FillDamFromXmlInput.cs
===================================================================
diff -u -r665 -r668
--- dam engine/trunk/src/Deltares.DamEngine.Interface/FillDamFromXmlInput.cs	(.../FillDamFromXmlInput.cs)	(revision 665)
+++ dam engine/trunk/src/Deltares.DamEngine.Interface/FillDamFromXmlInput.cs	(.../FillDamFromXmlInput.cs)	(revision 668)
@@ -121,7 +121,7 @@
                 {
                     if ((surfaceLine.Points == null) || (surfaceLine.Points.Length < 1))
                     {
-                        throw new NullReferenceException($"Surfaceline '{surfaceLine.Name}' has no points");
+                        throw new NullReferenceException(string.Format("Surfaceline '{0}' has no points", surfaceLine.Name));
                     }
                 }
             }
Index: dam clients/DamUI/trunk/src/Dam/Data/DamEngineIo/FillDamUiFromXmlInput.cs
===================================================================
diff -u -r666 -r668
--- dam clients/DamUI/trunk/src/Dam/Data/DamEngineIo/FillDamUiFromXmlInput.cs	(.../FillDamUiFromXmlInput.cs)	(revision 666)
+++ dam clients/DamUI/trunk/src/Dam/Data/DamEngineIo/FillDamUiFromXmlInput.cs	(.../FillDamUiFromXmlInput.cs)	(revision 668)
@@ -116,7 +116,7 @@
                 {
                     if ((surfaceLine.Points == null) || (surfaceLine.Points.Length < 1))
                     {
-                        throw new NullReferenceException($"Surfaceline '{surfaceLine.Name}' has no points");
+                        throw new NullReferenceException(string.Format("Surfaceline '{0}' has no points", surfaceLine.Name));
                     }
                 }
             }
Index: dam clients/DamUI/trunk/src/Dam/Data/DamEngineIo/FillXmlInputFromDamUi.cs
===================================================================
diff -u -r666 -r668
--- dam clients/DamUI/trunk/src/Dam/Data/DamEngineIo/FillXmlInputFromDamUi.cs	(.../FillXmlInputFromDamUi.cs)	(revision 666)
+++ dam clients/DamUI/trunk/src/Dam/Data/DamEngineIo/FillXmlInputFromDamUi.cs	(.../FillXmlInputFromDamUi.cs)	(revision 668)
@@ -150,11 +150,11 @@
                 {
                     if ((surfaceLine.CharacteristicPoints == null) || (surfaceLine.CharacteristicPoints.Count < 1))
                     {
-                        throw new NullReferenceException($"Surfaceline '{surfaceLine.Name}' has no characteristic points");
+                        throw new NullReferenceException(string.Format("Surfaceline '{0}' has no characteristic points", surfaceLine.Name));
                     }
                     if ((surfaceLine.Geometry == null) || (surfaceLine.Geometry.Count < 2))
                     {
-                        throw new NullReferenceException($"Surfaceline '{surfaceLine.Name}' has no points");
+                        throw new NullReferenceException(string.Format("Surfaceline '{0}' has no points", surfaceLine.Name));
                     }
                 }
             }
Index: dam engine/trunk/src/Deltares.DamEngine.Interface/FillXmlInputFromDam.cs
===================================================================
diff -u -r665 -r668
--- dam engine/trunk/src/Deltares.DamEngine.Interface/FillXmlInputFromDam.cs	(.../FillXmlInputFromDam.cs)	(revision 665)
+++ dam engine/trunk/src/Deltares.DamEngine.Interface/FillXmlInputFromDam.cs	(.../FillXmlInputFromDam.cs)	(revision 668)
@@ -127,11 +127,11 @@
                 {
                     if ((surfaceLine.CharacteristicPoints == null) || (surfaceLine.CharacteristicPoints.Count  < 1))
                     {
-                        throw new NullReferenceException($"Surfaceline '{surfaceLine.Name}' has no characteristic points");
+                        throw new NullReferenceException(string.Format("Surfaceline '{0}' has no characteristic points", surfaceLine.Name));
                     }
                     if ((surfaceLine.Geometry == null) || (surfaceLine.Geometry.Count < 2))
                     {
-                        throw new NullReferenceException($"Surfaceline '{surfaceLine.Name}' has no points");
+                        throw new NullReferenceException(string.Format("Surfaceline '{0}' has no points", surfaceLine.Name));
                     }
                 }
             }