Exception side panel (#213)

System.NullReferenceException: Object reference not set to an instance of an object.

at SoftwareIdeasModeler.Sidebars.ProjectTree.ProjectTreeSidebar. CanBeSelectionCopiedb__3e(FastTreeNode x)

at System.Linq.Enumerable.All[TSource](IEnumerable`1 source, Func`2 predicate)

at SoftwareIdeasModeler.Sidebars.ProjectTree.ProjectTreeSidebar.CanBeSelectionCopied()

at SoftwareIdeasModeler.Sidebars.ProjectTree.ProjectTreeSidebar.projectContextMenu_Opening(Object sender, CancelEventArgs e)

at System.Windows.Forms.ToolStripDropDown.OnOpening(CancelEventArgs e)

at System.Windows.Forms.ToolStripDropDown.SetVisibleCore(Boolean visible)

at System.Windows.Forms.ToolStripDropDown.Show(Control control, Point position)

at SoftwareIdeasModeler.Sidebars.ProjectTree.ProjectTreeSidebar.projectTree_NodeClick(Object sender, NodeClickEventArgs e)

at SoftwareIdeasModeler.Controls.FastTree.FastTree.OnMouseUp(MouseEventArgs e)

at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)

at System.Windows.Forms.Control.WndProc(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)