Getting error "Can't resolve OCI Stack Trace: at Quest.Toad.Oracle.ToadOracleHome.get_Is64Bit() " when trying to connect to Oracle (4335242)

Complete error message

System.ArgumentException Can't resolve OCI Stack Trace: at Quest.Toad.Oracle.ToadOracleHome.get_Is64Bit() at Quest.Toad.Oracle.OracleConnectionControl.ConnectionHome(ArrayList toadOracleHomes, OracleConnectMediator connectMediator) at Quest.Toad.Oracle.OracleConnectionControl.RefreshHomesUI(OracleConnectMediator connectMediator) at Quest.Toad.Oracle.OracleConnectionControl.RefreshUI(ConnectMediator connectOptions) at Quest.Toad.Oracle.OracleConnectionControl.InitUI(ConnectMediator connectOptions, ConnectionFormStyle displayStyle) at Quest.Toad.ConnectionManager.ConnectionPropertiesControl.CreateContainer(ConnectMediator connectOptions) at Quest.Toad.ConnectionManager.ConnectionPropertiesControl.GetContainer(ConnectMediator mediatorTemplate) at Quest.Toad.ConnectionManager.ConnectionPropertiesControl.groupSelectionControl1_GroupChanged(Object sender, EventArgs e) at Quest.Toad.Grouping.GroupSelectionControl.OnGroupChanged() at Quest.Toad.Grouping.GroupSelectionControl.DoClosePopup(PopupCloseMode closeMode) at DevExpress.XtraEditors.PopupBaseEdit.ClosePopup(PopupCloseMode closeMode) at Quest.Toad.Grouping.GroupSelectionControl.groupTree_MouseUp(Object sender, MouseEventArgs e) at System.Windows.Forms.Control.OnMouseUp(MouseEventArgs e) at DevExpress.XtraTreeList.TreeList.OnMouseUp(MouseEventArgs e) at Quest.Toad.TreeList.ToadTreeList.OnMouseUp(MouseEventArgs e) at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks) at System.Windows.Forms.Control.WndProc(Message& m) at DevExpress.XtraEditors.Container.EditorContainer.WndProc(Message& m) at DevExpress.XtraTreeList.TreeList.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)