diff --git a/mRemoteV1/Tree/ConnectionTreeModel.cs b/mRemoteV1/Tree/ConnectionTreeModel.cs
index 161de2f7..a28edd3d 100644
--- a/mRemoteV1/Tree/ConnectionTreeModel.cs
+++ b/mRemoteV1/Tree/ConnectionTreeModel.cs
@@ -42,7 +42,7 @@ namespace mRemoteNG.Tree
 
         public IEnumerable<ConnectionInfo> GetRecursiveChildList(ContainerInfo container)
         {
-            return container.GetRecursiveChildList();
+            return container?.GetRecursiveChildList() ?? new ConnectionInfo[0];
         }
 
         public void RenameNode(ConnectionInfo connectionInfo, string newName)
diff --git a/mRemoteV1/Tree/NodeSearcher.cs b/mRemoteV1/Tree/NodeSearcher.cs
index cb9bd823..e8b6c763 100644
--- a/mRemoteV1/Tree/NodeSearcher.cs
+++ b/mRemoteV1/Tree/NodeSearcher.cs
@@ -7,13 +7,13 @@ namespace mRemoteNG.Tree
 {
 	public class NodeSearcher
     {
-        private readonly ConnectionTreeModel _connectionTreeModel;
+        private readonly IConnectionTreeModel _connectionTreeModel;
 
         private List<ConnectionInfo> Matches { get; set; }
         public ConnectionInfo CurrentMatch { get; private set; }
 
 
-        public NodeSearcher(ConnectionTreeModel connectionTreeModel)
+        public NodeSearcher(IConnectionTreeModel connectionTreeModel)
         {
             _connectionTreeModel = connectionTreeModel;
         }
diff --git a/mRemoteV1/UI/Controls/ConnectionTree/ConnectionTree.cs b/mRemoteV1/UI/Controls/ConnectionTree/ConnectionTree.cs
index 5768b7da..6a86febf 100644
--- a/mRemoteV1/UI/Controls/ConnectionTree/ConnectionTree.cs
+++ b/mRemoteV1/UI/Controls/ConnectionTree/ConnectionTree.cs
@@ -24,7 +24,7 @@ namespace mRemoteNG.UI.Controls
         private bool _nodeInEditMode;
         private bool _allowEdit;
         private ConnectionContextMenu _contextMenu;
-        private ConnectionTreeModel _connectionTreeModel;
+        private IConnectionTreeModel _connectionTreeModel;
 
         public ConnectionInfo SelectedNode => (ConnectionInfo) SelectedObject;
 
@@ -38,7 +38,7 @@ namespace mRemoteNG.UI.Controls
 
         public ITreeNodeClickHandler<ConnectionInfo> SingleClickHandler { get; set; } = new TreeNodeCompositeClickHandler();
 
-        public ConnectionTreeModel ConnectionTreeModel
+        public IConnectionTreeModel ConnectionTreeModel
         {
             get { return _connectionTreeModel; }
             set
@@ -158,7 +158,7 @@ namespace mRemoteNG.UI.Controls
 		                   padding;
 		}
 
-        private void PopulateTreeView(ConnectionTreeModel newModel)
+        private void PopulateTreeView(IConnectionTreeModel newModel)
         {
             SetObjects(newModel.RootNodes);
             RegisterModelUpdateHandlers(newModel);
@@ -167,14 +167,14 @@ namespace mRemoteNG.UI.Controls
 			AutoResizeColumn(Columns[0]);
 		}
 
-        private void RegisterModelUpdateHandlers(ConnectionTreeModel newModel)
+        private void RegisterModelUpdateHandlers(IConnectionTreeModel newModel)
         {
             _puttySessionsManager.PuttySessionsCollectionChanged += OnPuttySessionsCollectionChanged;
             newModel.CollectionChanged += HandleCollectionChanged;
             newModel.PropertyChanged += HandleCollectionPropertyChanged;
         }
 
-        private void UnregisterModelUpdateHandlers(ConnectionTreeModel oldConnectionTreeModel)
+        private void UnregisterModelUpdateHandlers(IConnectionTreeModel oldConnectionTreeModel)
         {
             _puttySessionsManager.PuttySessionsCollectionChanged -= OnPuttySessionsCollectionChanged;
 
@@ -221,7 +221,7 @@ namespace mRemoteNG.UI.Controls
         #region ConnectionTree Behavior
         public RootNodeInfo GetRootConnectionNode()
         {
-            return (RootNodeInfo)ConnectionTreeModel.RootNodes.First(item => item is RootNodeInfo);
+            return (RootNodeInfo)ConnectionTreeModel.RootNodes.FirstOrDefault(item => item is RootNodeInfo);
         }
 
         public void Invoke(Action action)
diff --git a/mRemoteV1/UI/Controls/ConnectionTree/IConnectionTree.cs b/mRemoteV1/UI/Controls/ConnectionTree/IConnectionTree.cs
index 3edc9287..21cb74f4 100644
--- a/mRemoteV1/UI/Controls/ConnectionTree/IConnectionTree.cs
+++ b/mRemoteV1/UI/Controls/ConnectionTree/IConnectionTree.cs
@@ -8,7 +8,7 @@ namespace mRemoteNG.UI.Controls
 {
     public interface IConnectionTree
     {
-        ConnectionTreeModel ConnectionTreeModel { get; set; }
+        IConnectionTreeModel ConnectionTreeModel { get; set; }
 
         ConnectionInfo SelectedNode { get; }
 
diff --git a/mRemoteV1/UI/Window/ConnectionTreeWindow.cs b/mRemoteV1/UI/Window/ConnectionTreeWindow.cs
index 66af9c36..415e594c 100644
--- a/mRemoteV1/UI/Window/ConnectionTreeWindow.cs
+++ b/mRemoteV1/UI/Window/ConnectionTreeWindow.cs
@@ -27,7 +27,6 @@ namespace mRemoteNG.UI.Window
 	    public ConnectionTree ConnectionTree
 	    {
 	        get { return olvConnections; }
-            set { olvConnections = value; }
 	    }
 
 	    public ConnectionTreeWindow() : this(new DockContent())
@@ -43,6 +42,7 @@ namespace mRemoteNG.UI.Window
 		    SetConnectionTreeEventHandlers();
 		    Settings.Default.PropertyChanged += OnAppSettingsChanged;
 		    ApplyLanguage();
+            ConnectionTree.ConnectionTreeModel = Runtime.ConnectionsService.ConnectionTreeModel;
         }
 
 	    private void OnAppSettingsChanged(object o, PropertyChangedEventArgs propertyChangedEventArgs)
@@ -54,7 +54,6 @@ namespace mRemoteNG.UI.Window
             }
 
             PlaceSearchBar(Settings.Default.PlaceSearchBarAboveConnectionTree);
-
         }
 
         private void PlaceSearchBar(bool placeSearchBarAboveConnectionTree)