Index: Core/Common/src/Core.Common.Util/EnumTypeConverter.cs
===================================================================
diff -u -rac96d7c315129af851634ed5a4a6800b59ede718 -r73c16172f7ad09035b4c4eba030adccb1aa330c9
--- Core/Common/src/Core.Common.Util/EnumTypeConverter.cs	(.../EnumTypeConverter.cs)	(revision ac96d7c315129af851634ed5a4a6800b59ede718)
+++ Core/Common/src/Core.Common.Util/EnumTypeConverter.cs	(.../EnumTypeConverter.cs)	(revision 73c16172f7ad09035b4c4eba030adccb1aa330c9)
@@ -46,15 +46,19 @@
             var valueString = value as string;
             if (valueString != null)
             {
-                foreach (FieldInfo fieldInfo in EnumType.GetFields().Where(fieldInfo => valueString == GetDisplayName(fieldInfo, fieldInfo.Name)))
+                FieldInfo fieldInfo = EnumType.GetFields().FirstOrDefault(info => valueString == GetDisplayName(info, info.Name));
+
+                if (fieldInfo == null)
                 {
-                    return Enum.Parse(EnumType, fieldInfo.Name);
+                    throw new FormatException(string.Format(CultureInfo.CurrentCulture,
+                                                            Resources.ConvertFrom_Only_following_values_are_accepted_ParameterValues_0_,
+                                                            string.Join(", ", EnumType.GetFields(BindingFlags.Public | BindingFlags.Static)
+                                                                                      .Select(fi => GetDisplayName(fi, fi.Name)))));
                 }
-                throw new FormatException(string.Format(CultureInfo.CurrentCulture,
-                                                        Resources.ConvertFrom_Only_following_values_are_accepted_ParameterValues_0_,
-                                                        string.Join(", ", EnumType.GetFields(BindingFlags.Public | BindingFlags.Static)
-                                                                                  .Select(fi => GetDisplayName(fi, fi.Name)))));
+
+                return Enum.Parse(EnumType, fieldInfo.Name);
             }
+
             return base.ConvertFrom(context, culture, value);
         }
 
@@ -64,6 +68,7 @@
             {
                 return base.ConvertTo(context, culture, value, destinationType);
             }
+
             string valueString = value.ToString();
             FieldInfo fieldInfo = EnumType.GetField(valueString);
             return fieldInfo != null ? GetDisplayName(fieldInfo, valueString) : string.Empty;
Index: Core/Common/src/Core.Common.Util/NullableEnumConverter.cs
===================================================================
diff -u -rac96d7c315129af851634ed5a4a6800b59ede718 -r73c16172f7ad09035b4c4eba030adccb1aa330c9
--- Core/Common/src/Core.Common.Util/NullableEnumConverter.cs	(.../NullableEnumConverter.cs)	(revision ac96d7c315129af851634ed5a4a6800b59ede718)
+++ Core/Common/src/Core.Common.Util/NullableEnumConverter.cs	(.../NullableEnumConverter.cs)	(revision 73c16172f7ad09035b4c4eba030adccb1aa330c9)
@@ -47,14 +47,18 @@
             {
                 throw new NotSupportedException("Cannot convert from (null).");
             }
+
             var valueString = value as string;
             if (valueString != null)
             {
-                foreach (FieldInfo fieldInfo in UnderlyingType.GetFields().Where(fieldInfo => valueString == GetDisplayName(fieldInfo)))
+                FieldInfo fieldInfo = UnderlyingType.GetFields().FirstOrDefault(info => valueString == GetDisplayName(info));
+
+                if (fieldInfo != null)
                 {
                     return Enum.Parse(UnderlyingType, fieldInfo.Name);
                 }
             }
+
             return base.ConvertFrom(context, culture, value);
         }
 
Index: Core/Components/src/Core.Components.GraphSharp/Data/PointedTreeElementVertex.cs
===================================================================
diff -u -rf46ba440e51db6e6cb1c02375b6afa771eb94570 -r73c16172f7ad09035b4c4eba030adccb1aa330c9
--- Core/Components/src/Core.Components.GraphSharp/Data/PointedTreeElementVertex.cs	(.../PointedTreeElementVertex.cs)	(revision f46ba440e51db6e6cb1c02375b6afa771eb94570)
+++ Core/Components/src/Core.Components.GraphSharp/Data/PointedTreeElementVertex.cs	(.../PointedTreeElementVertex.cs)	(revision 73c16172f7ad09035b4c4eba030adccb1aa330c9)
@@ -47,23 +47,15 @@
         /// <param name="lineWidth">The line width of the vertex.</param>
         /// <param name="type">The type of the vertex.</param>
         /// <param name="isSelectable">Indicator whether the vertex is selectable.</param>
-        /// <exception cref="ArgumentNullException">Thrown when <paramref name="content"/>
-        /// <paramref name="fillColor"/> or <paramref name="lineColor"/> is <c>null</c>.</exception>
+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="content"/> is <c>null</c>.</exception>
         public PointedTreeElementVertex(string content, Color fillColor, Color lineColor, int lineWidth,
                                         PointedTreeVertexType type, bool isSelectable)
         {
             if (content == null)
             {
                 throw new ArgumentNullException(nameof(content));
             }
-            if (fillColor == null)
-            {
-                throw new ArgumentNullException(nameof(fillColor));
-            }
-            if (lineColor == null)
-            {
-                throw new ArgumentNullException(nameof(lineColor));
-            }
+
             Content = content;
             FillColor = new SolidColorBrush(fillColor);
             LineColor = new SolidColorBrush(lineColor);
Index: Ringtoets/Common/src/Ringtoets.Common.Forms/Views/RingtoetsMapControl.cs
===================================================================
diff -u -rfcad48d7beb394e1ac15cfe4289a7381e05aa883 -r73c16172f7ad09035b4c4eba030adccb1aa330c9
--- Ringtoets/Common/src/Ringtoets.Common.Forms/Views/RingtoetsMapControl.cs	(.../RingtoetsMapControl.cs)	(revision fcad48d7beb394e1ac15cfe4289a7381e05aa883)
+++ Ringtoets/Common/src/Ringtoets.Common.Forms/Views/RingtoetsMapControl.cs	(.../RingtoetsMapControl.cs)	(revision 73c16172f7ad09035b4c4eba030adccb1aa330c9)
@@ -81,9 +81,7 @@
             backgroundDataObserver.Observable = backgroundData;
 
             mapControl.Data = data;
-            mapControl.BackgroundMapData = backgroundData != null
-                                               ? BackgroundDataConverter.ConvertFrom(backgroundData)
-                                               : null;
+            mapControl.BackgroundMapData = BackgroundDataConverter.ConvertFrom(backgroundData);
         }
 
         /// <summary>