Index: Application/Riskeer/src/Application.Riskeer/App.xaml.cs
===================================================================
diff -u -rb95e081a1d550f0a651010558cd3b9484dbcf113 -r18039f491c06f9a65491a1fef17d84aa1b1d3f07
--- Application/Riskeer/src/Application.Riskeer/App.xaml.cs	(.../App.xaml.cs)	(revision b95e081a1d550f0a651010558cd3b9484dbcf113)
+++ Application/Riskeer/src/Application.Riskeer/App.xaml.cs	(.../App.xaml.cs)	(revision 18039f491c06f9a65491a1fef17d84aa1b1d3f07)
@@ -199,10 +199,7 @@
                     fileToOpen = potentialPath;
                     return true;
                 }
-                catch (ArgumentException)
-                {
-                    return false;
-                }
+                catch (ArgumentException) {}
             }
 
             return false;
@@ -236,14 +233,17 @@
 
             try
             {
-                if (!AcquireSingleInstancePerUserMutex())
+                if (!Debugger.IsAttached)
                 {
-                    MessageBox.Show(CoreCommonGuiResources.App_ShutdownIfNotFirstInstance_Cannot_start_multiple_instances_of_Riskeer_Please_close_the_other_instance_first);
-                    Shutdown(1);
-                    return true; //done here
-                }
+                    if (!AcquireSingleInstancePerUserMutex())
+                    {
+                        MessageBox.Show(CoreCommonGuiResources.App_ShutdownIfNotFirstInstance_Cannot_start_multiple_instances_of_Riskeer_Please_close_the_other_instance_first);
+                        Shutdown(1);
+                        return true; //done here
+                    }
 
-                hasMutex = true;
+                    hasMutex = true;
+                }
             }
             finally
             {
@@ -281,12 +281,23 @@
 
         private static bool AcquireSingleInstancePerUserMutex()
         {
-            bool createdNew;
+            var createdNew = false;
+            try
+            {
+                //include the user name in the (global) mutex to ensure we limit only the number of instances per 
+                //user, not per system (essential on for example Citrix systems).
 
-            // Include the user name in the (global) mutex to ensure we limit only the number of instances per 
-            // user, not per system (essential on for example Citrix systems).
-            singleInstanceMutex = new Mutex(true, $"Riskeer-single-instance-mutex-{Environment.UserName}", out createdNew);
+                //include the application name in the mutex to ensure we are allowed to start for example 'Sobek' 
+                //and 'Morphan' side by side.
+                string applicationName = ConfigurationManager.AppSettings.AllKeys.Contains("applicationName")
+                                             ? ConfigurationManager.AppSettings["applicationName"]
+                                             : string.Empty;
 
+                string mutexName = $"Riskeer-single-instance-mutex-{Environment.UserName}-{applicationName}";
+                singleInstanceMutex = new Mutex(true, mutexName, out createdNew);
+            }
+            catch (AbandonedMutexException) {} //might throw an abandoned mutex exception if the previous DS instance forcefully exited.
+
             return createdNew;
         }
 
Index: Core/Common/src/Core.Common.Base/Geometry/Math2D.cs
===================================================================
diff -u -r16b0b53af7f16d085e51f880d6d09225be267916 -r18039f491c06f9a65491a1fef17d84aa1b1d3f07
--- Core/Common/src/Core.Common.Base/Geometry/Math2D.cs	(.../Math2D.cs)	(revision 16b0b53af7f16d085e51f880d6d09225be267916)
+++ Core/Common/src/Core.Common.Base/Geometry/Math2D.cs	(.../Math2D.cs)	(revision 18039f491c06f9a65491a1fef17d84aa1b1d3f07)
@@ -470,9 +470,11 @@
                                : Segment2DIntersectSegment2DResult.CreateNoIntersectResult();
                 }
 
-                return IsPointInCollinearSegment(segment1.FirstPoint, segment2)
-                           ? Segment2DIntersectSegment2DResult.CreateIntersectionResult(segment1.FirstPoint)
-                           : Segment2DIntersectSegment2DResult.CreateNoIntersectResult();
+                {
+                    return IsPointInCollinearSegment(segment1.FirstPoint, segment2)
+                               ? Segment2DIntersectSegment2DResult.CreateIntersectionResult(segment1.FirstPoint)
+                               : Segment2DIntersectSegment2DResult.CreateNoIntersectResult();
+                }
             }
 
             return IsPointInCollinearSegment(segment2.FirstPoint, segment1)
Index: Core/Common/src/Core.Common.Controls.TreeView/TreeViewControl.cs
===================================================================
diff -u -r22f739a06f914021000e3167894efa0145da5bed -r18039f491c06f9a65491a1fef17d84aa1b1d3f07
--- Core/Common/src/Core.Common.Controls.TreeView/TreeViewControl.cs	(.../TreeViewControl.cs)	(revision 22f739a06f914021000e3167894efa0145da5bed)
+++ Core/Common/src/Core.Common.Controls.TreeView/TreeViewControl.cs	(.../TreeViewControl.cs)	(revision 18039f491c06f9a65491a1fef17d84aa1b1d3f07)
@@ -93,7 +93,7 @@
 
         public event EventHandler DataDoubleClick;
         public event EventHandler SelectedDataChanged;
-        public event EventHandler<EventArgs<object>> DataDeleted;
+        public event EventHandler<EventArgs<object>> DataDeleted; // TODO; Way to explicit!
 
         /// <summary>
         /// Creates a new instance of <see cref="TreeViewControl"/>.
Index: Core/Common/src/Core.Common.Gui/Converters/KeyValueExpandableArrayConverter.cs
===================================================================
diff -u -r70a85081f14d88ed379599379c0bbb95f1b7489f -r18039f491c06f9a65491a1fef17d84aa1b1d3f07
--- Core/Common/src/Core.Common.Gui/Converters/KeyValueExpandableArrayConverter.cs	(.../KeyValueExpandableArrayConverter.cs)	(revision 70a85081f14d88ed379599379c0bbb95f1b7489f)
+++ Core/Common/src/Core.Common.Gui/Converters/KeyValueExpandableArrayConverter.cs	(.../KeyValueExpandableArrayConverter.cs)	(revision 18039f491c06f9a65491a1fef17d84aa1b1d3f07)
@@ -82,7 +82,7 @@
         /// </summary>
         private class ArrayPropertyDescriptor : SimplePropertyDescriptor
         {
-            private readonly object propertyValue;
+            private readonly object value;
 
             /// <summary>
             /// Creates a new instance of <see cref="ArrayPropertyDescriptor"/>.
@@ -93,7 +93,7 @@
             public ArrayPropertyDescriptor(Type elementType, string name, object value)
                 : base(elementType, name, value.GetType())
             {
-                propertyValue = value;
+                this.value = value;
             }
 
             public override bool IsReadOnly
@@ -106,10 +106,10 @@
 
             public override object GetValue(object component)
             {
-                return propertyValue;
+                return value;
             }
 
-            public override void SetValue(object component, object value)
+            public override void SetValue(object component, object valueToSet)
             {
                 throw new NotSupportedException();
             }