Index: Core/Gui/src/Core.Gui/GuiCore.cs
===================================================================
diff -u -re848b504d265b0c9443afc069a3b31227af46409 -r3ea7b672d4425d0fa1c7edd7ab7b92e7e2ea0153
--- Core/Gui/src/Core.Gui/GuiCore.cs	(.../GuiCore.cs)	(revision e848b504d265b0c9443afc069a3b31227af46409)
+++ Core/Gui/src/Core.Gui/GuiCore.cs	(.../GuiCore.cs)	(revision 3ea7b672d4425d0fa1c7edd7ab7b92e7e2ea0153)
@@ -23,7 +23,6 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.ComponentModel;
-using System.Diagnostics;
 using System.Globalization;
 using System.Linq;
 using System.Reflection;
@@ -61,9 +60,6 @@
     {
         private static readonly ILog log = LogManager.GetLogger(typeof(GuiCore));
 
-        private static bool isAlreadyRunningInstanceOfIGui;
-        private static string instanceCreationStackTrace;
-
         private readonly string applicationTitle;
         private readonly Observer projectObserver;
         private ISelectionProvider currentSelectionProvider;
@@ -78,21 +74,9 @@
         /// <param name="projectMigrator">The project migrator.</param>
         /// <param name="projectFactory">The project factory.</param>
         /// <param name="fixedSettings">The fixed settings.</param>
-        /// <exception cref="InvalidOperationException">Thrown when another <see cref="GuiCore"/>
-        /// instance is running.</exception>
         /// <exception cref="ArgumentNullException">Thrown when any parameter is <c>null</c>.</exception>
         public GuiCore(IMainWindow mainWindow, IStoreProject projectStore, IMigrateProject projectMigrator, IProjectFactory projectFactory, GuiCoreSettings fixedSettings)
         {
-            // Error detection code, make sure we use only a single instance of GuiCore at a time
-            if (isAlreadyRunningInstanceOfIGui)
-            {
-                isAlreadyRunningInstanceOfIGui = false; // Reset so that the consecutive creations won't fail
-                throw new InvalidOperationException(
-                    string.Format(CultureInfo.CurrentCulture,
-                                  Resources.GuiCore_Only_a_single_instance_is_allowed_at_the_same_time_per_process_Make_sure_that_the_previous_instance_was_disposed_correctly_stack_trace_0,
-                                  instanceCreationStackTrace));
-            }
-
             if (mainWindow == null)
             {
                 throw new ArgumentNullException(nameof(mainWindow));
@@ -122,9 +106,6 @@
             FixedSettings = fixedSettings;
             MainWindow = mainWindow;
 
-            isAlreadyRunningInstanceOfIGui = true;
-            instanceCreationStackTrace = new StackTrace().ToString();
-
             Plugins = new List<PluginBase>();
 
             viewCommandHandler = new ViewCommandHandler(this, this, this);
@@ -328,9 +309,6 @@
             #endregion
 
             GC.Collect();
-
-            instanceCreationStackTrace = "";
-            isAlreadyRunningInstanceOfIGui = false;
         }
 
         private void DeactivatePlugin(PluginBase plugin)
Index: Core/Gui/src/Core.Gui/Properties/Resources.Designer.cs
===================================================================
diff -u -re848b504d265b0c9443afc069a3b31227af46409 -r3ea7b672d4425d0fa1c7edd7ab7b92e7e2ea0153
--- Core/Gui/src/Core.Gui/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision e848b504d265b0c9443afc069a3b31227af46409)
+++ Core/Gui/src/Core.Gui/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 3ea7b672d4425d0fa1c7edd7ab7b92e7e2ea0153)
@@ -1246,16 +1246,6 @@
         }
         
         /// <summary>
-        ///   Looks up a localized string similar to Slechts één instantie van de grafische interface is toegestaan per proces. Zorg ervoor dat de vorige instantie correct opgeruimd is. &apos;Stack trace&apos;: {0}.
-        /// </summary>
-        public static string GuiCore_Only_a_single_instance_is_allowed_at_the_same_time_per_process_Make_sure_that_the_previous_instance_was_disposed_correctly_stack_trace_0 {
-            get {
-                return ResourceManager.GetString("GuiCore_Only_a_single_instance_is_allowed_at_the_same_time_per_process_Make_sure_" +
-                        "that_the_previous_instance_was_disposed_correctly_stack_trace_0", resourceCulture);
-            }
-        }
-        
-        /// <summary>
         ///   Looks up a localized string similar to Gestart in {0:f2} seconden..
         /// </summary>
         public static string GuiCore_Run_Started_in_0_f2_sec {
Index: Core/Gui/src/Core.Gui/Properties/Resources.resx
===================================================================
diff -u -re848b504d265b0c9443afc069a3b31227af46409 -r3ea7b672d4425d0fa1c7edd7ab7b92e7e2ea0153
--- Core/Gui/src/Core.Gui/Properties/Resources.resx	(.../Resources.resx)	(revision e848b504d265b0c9443afc069a3b31227af46409)
+++ Core/Gui/src/Core.Gui/Properties/Resources.resx	(.../Resources.resx)	(revision 3ea7b672d4425d0fa1c7edd7ab7b92e7e2ea0153)
@@ -223,9 +223,6 @@
   <data name="information" type="System.Resources.ResXFileRef, System.Windows.Forms">
     <value>..\Resources\information.png;System.Drawing.Bitmap, System.Drawing, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</value>
   </data>
-  <data name="GuiCore_Only_a_single_instance_is_allowed_at_the_same_time_per_process_Make_sure_that_the_previous_instance_was_disposed_correctly_stack_trace_0" xml:space="preserve">
-    <value>Slechts één instantie van de grafische interface is toegestaan per proces. Zorg ervoor dat de vorige instantie correct opgeruimd is. 'Stack trace': {0}</value>
-  </data>
   <data name="MessageWindow_MessageWindow_Messages" xml:space="preserve">
     <value>Berichten</value>
   </data>
Index: Core/Gui/test/Core.Gui.Test/GuiCoreTest.cs
===================================================================
diff -u -r5f736cce56b144cb9d28cbc85efd738b9a90a725 -r3ea7b672d4425d0fa1c7edd7ab7b92e7e2ea0153
--- Core/Gui/test/Core.Gui.Test/GuiCoreTest.cs	(.../GuiCoreTest.cs)	(revision 5f736cce56b144cb9d28cbc85efd738b9a90a725)
+++ Core/Gui/test/Core.Gui.Test/GuiCoreTest.cs	(.../GuiCoreTest.cs)	(revision 3ea7b672d4425d0fa1c7edd7ab7b92e7e2ea0153)
@@ -242,34 +242,6 @@
         }
 
         [Test]
-        public void Constructor_ConstructedAfterAnotherInstanceHasBeenCreated_ThrowsInvalidOperationException()
-        {
-            // Setup
-            var mocks = new MockRepository();
-            var projectStore = mocks.Stub<IStoreProject>();
-            var projectMigrator = mocks.Stub<IMigrateProject>();
-            var projectFactory = mocks.Stub<IProjectFactory>();
-            mocks.ReplayAll();
-
-            var guiCoreSettings = new GuiCoreSettings();
-
-            using (var mainWindow = new MainWindow())
-            using (new GuiCore(mainWindow, projectStore, projectMigrator, projectFactory, guiCoreSettings))
-            {
-                // Call
-                void Call()
-                {
-                    using (new GuiCore(mainWindow, projectStore, projectMigrator, projectFactory, guiCoreSettings)) {}
-                }
-
-                // Assert
-                Assert.Throws<InvalidOperationException>(Call);
-            }
-
-            mocks.VerifyAll();
-        }
-
-        [Test]
         public void Dispose_WithPlugin_PluginRemoved()
         {
             // Setup