Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object
in <0x00009> System.Windows.Forms.Document+Marker:op_LessThan (Marker lhs, Marker rhs)
in <0x001af> System.Windows.Forms.Document:SetSelectionToCaret (Boolean start)
in <0x000a7> System.Windows.Forms.TextBoxBase:TextBoxBase_MouseUp (System.Object sender, System.Windows.Forms.MouseEventArgs e)
in (wrapper delegate-invoke) System.MulticastDelegate:invoke_void_object_MouseEventArgs (object,System.Windows.Forms.MouseEventArgs)
in <0x00023> System.Windows.Forms.Control:OnMouseUp (System.Windows.Forms.MouseEventArgs e)
in <0x00698> System.Windows.Forms.Control:WndProc (System.Windows.Forms.Message m)
in <0x00367> System.Windows.Forms.TextBoxBase:WndProc (System.Windows.Forms.Message m)
in <0x0000d> System.Windows.Forms.RichTextBox:WndProc (System.Windows.Forms.Message m)
in <0x00014> System.Windows.Forms.Control+ControlNativeWindow:WndProc (System.Windows.Forms.Message m)
in <0x0011e> System.Windows.Forms.NativeWindow:WndProc (IntPtr hWnd, Msg msg, IntPtr wParam, IntPtr lParam)
in <0x00016> System.Windows.Forms.XplatUIX11:DispatchMessage (System.Windows.Forms.MSG msg)
in <0x00015> System.Windows.Forms.XplatUI:DispatchMessage (System.Windows.Forms.MSG msg)
in <0x00610> System.Windows.Forms.Application:RunLoop (Boolean Modal, System.Windows.Forms.ApplicationContext context)
in <0x00024> System.Windows.Forms.Application:Run (System.Windows.Forms.Form mainForm)
in <0x00024> Nexxia.FormStartup:Main (System.String[] args)