Index: Core/Common/src/Core.Common.Controls.TreeView/DragDropHandler.cs
===================================================================
diff -u -r2ec08867a90646f09852fb338e18b70c6176b5ac -rb060eed93e2290dbe0a36da6e5556002625b73d5
--- Core/Common/src/Core.Common.Controls.TreeView/DragDropHandler.cs	(.../DragDropHandler.cs)	(revision 2ec08867a90646f09852fb338e18b70c6176b5ac)
+++ Core/Common/src/Core.Common.Controls.TreeView/DragDropHandler.cs	(.../DragDropHandler.cs)	(revision b060eed93e2290dbe0a36da6e5556002625b73d5)
@@ -116,7 +116,7 @@
             var treeNodeInfo = getTreeNodeInfoForData(nodeDropTarget.Tag);
 
             DragOperations allowedOperations = treeNodeInfo.CanDrop != null
-                                                   ? treeNodeInfo.CanDrop(nodeDragging.Tag, nodeDropTarget.Tag, ToDragOperation(e.AllowedEffect))
+                                                   ? treeNodeInfo.CanDrop(nodeDragging.Tag, nodeDropTarget.Tag)
                                                    : DragOperations.None;
 
             e.Effect = ToDragDropEffects(allowedOperations);
@@ -129,7 +129,7 @@
             // Determine whether or not the node can be dropped based on the allowed operations.
             // A node can also be a valid drop target if it is the root item (nodeDragging.Parent == null).
             var dragOperations = treeNodeInfo.CanDrop != null
-                                     ? treeNodeInfo.CanDrop(nodeDragging.Tag, nodeDropTarget.Tag, allowedOperations)
+                                     ? treeNodeInfo.CanDrop(nodeDragging.Tag, nodeDropTarget.Tag)
                                      : DragOperations.None;
 
             if (DragOperations.None != dragOperations)
@@ -204,11 +204,6 @@
             }
         }
 
-        private DragOperations ToDragOperation(DragDropEffects dragDropEffects)
-        {
-            return (DragOperations) Enum.Parse(typeof(DragOperations), dragDropEffects.ToString());
-        }
-
         private bool IsChildOf(TreeNode childNode, TreeNode node)
         {
             while (childNode != null && childNode.Parent != null)
Index: Core/Common/src/Core.Common.Controls.TreeView/TreeNodeInfo.cs
===================================================================
diff -u -r2ec08867a90646f09852fb338e18b70c6176b5ac -rb060eed93e2290dbe0a36da6e5556002625b73d5
--- Core/Common/src/Core.Common.Controls.TreeView/TreeNodeInfo.cs	(.../TreeNodeInfo.cs)	(revision 2ec08867a90646f09852fb338e18b70c6176b5ac)
+++ Core/Common/src/Core.Common.Controls.TreeView/TreeNodeInfo.cs	(.../TreeNodeInfo.cs)	(revision b060eed93e2290dbe0a36da6e5556002625b73d5)
@@ -139,11 +139,10 @@
         /// Gets or sets a function for checking whether or not the tree node can be dropped to another location.
         /// The first <c>object</c> parameter represents the data of the tree node which is dragged.
         /// The second <c>object</c> parameter represents the data of the tree node being considered as drop target.
-        /// The <see cref="DragOperations"/> parameter represents the supported drop operations for the tree node which is dragged.
         /// The <see cref="DragOperations"/> return value indicates what operation is valid when the tree node is dropped onto the drop target.
         /// </summary>
         /// <remarks>When dragging a node, the <see cref="CanDrop"/> function of the <see cref="TreeNodeInfo"/> of the drop target should be called.</remarks>
-        public Func<object, object, DragOperations, DragOperations> CanDrop { get; set; }
+        public Func<object, object, DragOperations> CanDrop { get; set; }
 
         /// <summary>
         /// Gets or sets a function for checking whether or not the tree node can be inserted into the drop target at a specific index.
@@ -285,11 +284,10 @@
         /// Gets or sets a function for checking whether or not the tree node can be dropped to another location.
         /// The first <c>object</c> parameter represents the data of the tree node which is dragged.
         /// The second <c>object</c> parameter represents the data of the tree node being considered as drop target.
-        /// The <see cref="DragOperations"/> parameter represents the supported drop operations for the tree node which is dragged.
         /// The <see cref="DragOperations"/> return value indicates what operation is valid when the tree node is dropped onto the drop target.
         /// </summary>
         /// <remarks>When dragging a node, the <see cref="CanDrop"/> function of the <see cref="TreeNodeInfo"/> of the drop target should be called.</remarks>
-        public Func<object, object, DragOperations, DragOperations> CanDrop { get; set; }
+        public Func<object, object, DragOperations> CanDrop { get; set; }
 
         /// <summary>
         /// Gets or sets a function for checking whether or not the tree node can be inserted into the drop target at a specific index.
@@ -362,8 +360,8 @@
                               ? (tag, parentTag) => treeNodeInfo.CanDrag((TData) tag, parentTag)
                               : (Func<object, object, bool>) null,
                 CanDrop = treeNodeInfo.CanDrop != null
-                              ? (draggedTag, targetTag, dragOperations) => treeNodeInfo.CanDrop(draggedTag, targetTag, dragOperations)
-                              : (Func<object, object, DragOperations, DragOperations>) null,
+                              ? (draggedTag, targetTag) => treeNodeInfo.CanDrop(draggedTag, targetTag)
+                              : (Func<object, object, DragOperations>) null,
                 CanInsert = treeNodeInfo.CanInsert != null
                                 ? (draggedTag, targetTag) => treeNodeInfo.CanInsert(draggedTag, targetTag)
                                 : (Func<object, object, bool>) null,
Index: Core/Plugins/src/Core.Plugins.OxyPlot/Legend/LegendView.cs
===================================================================
diff -u -r2ec08867a90646f09852fb338e18b70c6176b5ac -rb060eed93e2290dbe0a36da6e5556002625b73d5
--- Core/Plugins/src/Core.Plugins.OxyPlot/Legend/LegendView.cs	(.../LegendView.cs)	(revision 2ec08867a90646f09852fb338e18b70c6176b5ac)
+++ Core/Plugins/src/Core.Plugins.OxyPlot/Legend/LegendView.cs	(.../LegendView.cs)	(revision b060eed93e2290dbe0a36da6e5556002625b73d5)
@@ -149,11 +149,11 @@
 
         # region ChartDataCollection
 
-        private DragOperations BaseChartCanDrop(object draggedData, object targetData, DragOperations validOperations)
+        private DragOperations BaseChartCanDrop(object draggedData, object targetData)
         {
             if (draggedData is ChartData)
             {
-                return validOperations;
+                return DragOperations.Move;
             }
 
             return DragOperations.None;
Index: Core/Plugins/test/Core.Plugins.OxyPlot.Test/Legend/ChartDataCollectionTreeNodeInfoTest.cs
===================================================================
diff -u -r2ec08867a90646f09852fb338e18b70c6176b5ac -rb060eed93e2290dbe0a36da6e5556002625b73d5
--- Core/Plugins/test/Core.Plugins.OxyPlot.Test/Legend/ChartDataCollectionTreeNodeInfoTest.cs	(.../ChartDataCollectionTreeNodeInfoTest.cs)	(revision 2ec08867a90646f09852fb338e18b70c6176b5ac)
+++ Core/Plugins/test/Core.Plugins.OxyPlot.Test/Legend/ChartDataCollectionTreeNodeInfoTest.cs	(.../ChartDataCollectionTreeNodeInfoTest.cs)	(revision b060eed93e2290dbe0a36da6e5556002625b73d5)
@@ -111,17 +111,15 @@
         }
 
         [Test]
-        [TestCase(DragOperations.Move)]
-        [TestCase(DragOperations.None)]
-        public void CanDrop_SourceNodeTagIsNoChartData_ReturnsDragOperationsNone(DragOperations validDragOperations)
+        public void CanDrop_SourceNodeTagIsNoChartData_ReturnsDragOperationsNone()
         {
             // Setup
             var chartDataCollection = mocks.StrictMock<ChartDataCollection>(new List<ChartData>());
 
             mocks.ReplayAll();
 
             // Call
-            var validOperations = info.CanDrop(new object(), chartDataCollection, validDragOperations);
+            var validOperations = info.CanDrop(new object(), chartDataCollection);
 
             // Assert
             Assert.AreEqual(DragOperations.None, validOperations);
@@ -130,9 +128,7 @@
         }
 
         [Test]
-        [TestCase(DragOperations.Move)]
-        [TestCase(DragOperations.None)]
-        public void CanDrop_SourceNodeTagIsChartData_ReturnsGivenDragOperations(DragOperations validDragOperations)
+        public void CanDrop_SourceNodeTagIsChartData_ReturnsDragOperationsMove()
         {
             // Setup
             var chartData = mocks.StrictMock<ChartData>();
@@ -141,10 +137,10 @@
             mocks.ReplayAll();
 
             // Call
-            var validOperations = info.CanDrop(chartData, chartDataCollection, validDragOperations);
+            var validOperations = info.CanDrop(chartData, chartDataCollection);
 
             // Assert
-            Assert.AreEqual(validDragOperations, validOperations);
+            Assert.AreEqual(DragOperations.Move, validOperations);
 
             mocks.VerifyAll();
         }
Index: Ringtoets/Piping/src/Ringtoets.Piping.Plugin/PipingGuiPlugin.cs
===================================================================
diff -u -r2ec08867a90646f09852fb338e18b70c6176b5ac -rb060eed93e2290dbe0a36da6e5556002625b73d5
--- Ringtoets/Piping/src/Ringtoets.Piping.Plugin/PipingGuiPlugin.cs	(.../PipingGuiPlugin.cs)	(revision 2ec08867a90646f09852fb338e18b70c6176b5ac)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Plugin/PipingGuiPlugin.cs	(.../PipingGuiPlugin.cs)	(revision b060eed93e2290dbe0a36da6e5556002625b73d5)
@@ -702,11 +702,11 @@
             return true;
         }
 
-        private DragOperations PipingCalculationGroupContextCanDrop(object draggedData, object targetData, DragOperations validOperations)
+        private DragOperations PipingCalculationGroupContextCanDrop(object draggedData, object targetData)
         {
             if (GetAsIPipingCalculationItem(draggedData) != null && NodesHaveSameParentFailureMechanism(draggedData, targetData))
             {
-                return validOperations;
+                return DragOperations.Move;
             }
 
             return DragOperations.None;
Index: Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/TreeNodeInfos/PipingCalculationGroupContextTreeNodeInfoTest.cs
===================================================================
diff -u -ra1de055e3698f610875e623d39f4526970568cef -rb060eed93e2290dbe0a36da6e5556002625b73d5
--- Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/TreeNodeInfos/PipingCalculationGroupContextTreeNodeInfoTest.cs	(.../PipingCalculationGroupContextTreeNodeInfoTest.cs)	(revision a1de055e3698f610875e623d39f4526970568cef)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/TreeNodeInfos/PipingCalculationGroupContextTreeNodeInfoTest.cs	(.../PipingCalculationGroupContextTreeNodeInfoTest.cs)	(revision b060eed93e2290dbe0a36da6e5556002625b73d5)
@@ -139,7 +139,7 @@
             {
                 case DragDropTestMethod.CanDrop:
                     // Call
-                    DragOperations supportedOperations = info.CanDrop(draggedItemContext, targetGroupContext, DragOperations.Move);
+                    DragOperations supportedOperations = info.CanDrop(draggedItemContext, targetGroupContext);
 
                     // Assert
                     Assert.AreEqual(DragOperations.Move, supportedOperations);
@@ -185,7 +185,7 @@
             {
                 case DragDropTestMethod.CanDrop:
                     // Call
-                    DragOperations supportedOperations = info.CanDrop(draggedItemContext, targetGroupContext, DragOperations.Move);
+                    DragOperations supportedOperations = info.CanDrop(draggedItemContext, targetGroupContext);
 
                     // Assert
                     Assert.AreEqual(DragOperations.None, supportedOperations);