Index: Ringtoets/Common/test/Ringtoets.Common.Forms.Test/Views/CalculatableViewTest.cs
===================================================================
diff -u -r888f6cdc81e8fb6d6a5b9baadf6395f209008836 -rc6609aa18c44e976105aa8f434616576aeb7f677
--- Ringtoets/Common/test/Ringtoets.Common.Forms.Test/Views/CalculatableViewTest.cs	(.../CalculatableViewTest.cs)	(revision 888f6cdc81e8fb6d6a5b9baadf6395f209008836)
+++ Ringtoets/Common/test/Ringtoets.Common.Forms.Test/Views/CalculatableViewTest.cs	(.../CalculatableViewTest.cs)	(revision c6609aa18c44e976105aa8f434616576aeb7f677)
@@ -23,6 +23,7 @@
 using System.Linq;
 using System.Windows.Forms;
 using Core.Common.Controls.Views;
+using Core.Common.Utils.Reflection;
 using NUnit.Extensions.Forms;
 using NUnit.Framework;
 using Ringtoets.Common.Forms.Views;
@@ -178,18 +179,39 @@
         }
 
         [Test]
-        public void GivenFullyConfiguredView_WhenNoRowsSelected_ThenCalculateForSelectedButtonDisabled()
+        public void GivenFullyConfiguredView_WhenNoRowsSelected_ThenCalculateForSelectedButtonDisabledAndErrorMessageProvided()
         {
             // Given & When
             TestCalculatableView view = ShowFullyConfiguredTestCalculatableView();
 
             // Then
             var button = (Button) view.Controls.Find("CalculateForSelectedButton", true)[0];
             Assert.IsFalse(button.Enabled);
-            Assert.IsEmpty(view.ObjectsToCalculate);
+
+            var errorProvider = TypeUtils.GetField<ErrorProvider>(view, "CalculateForSelectedButtonErrorProvider");
+            Assert.AreEqual("Er zijn geen berekeningen geselecteerd.", errorProvider.GetError(button));
         }
 
         [Test]
+        public void GivenFullyConfiguredView_WhenRowsSelected_ThenCalculateForSelectedButtonEnabledAndNoErrorMessageProvided()
+        {
+            // Given & When
+            TestCalculatableView view = ShowFullyConfiguredTestCalculatableView();
+
+            var dataGridView = (DataGridView) view.Controls.Find("dataGridView", true)[0];
+
+            DataGridViewRowCollection rows = dataGridView.Rows;
+            rows[0].Cells[calculateColumnIndex].Value = true;
+
+            // Then
+            var button = (Button) view.Controls.Find("CalculateForSelectedButton", true)[0];
+            Assert.IsTrue(button.Enabled);
+
+            var errorProvider = TypeUtils.GetField<ErrorProvider>(view, "CalculateForSelectedButtonErrorProvider");
+            Assert.AreEqual("", errorProvider.GetError(button));
+        }
+
+        [Test]
         public void CalculateForSelectedButton_OneSelected_CallsCalculateHandleCalculateSelectedObjects()
         {
             // Setup