Error when insert a shape layer

tengu8740[CodePlex]
I can't send a report with internal tool.
The version is 1.7.3
When i try to load a shape i see this error but the shape is correctly loaded and viewed

System.NullReferenceException: Riferimento a un oggetto non impostato su un'istanza di oggetto.

in DotSpatial.Controls.Legend.HideEditBox()
in DotSpatial.Controls.Legend.OnMouseDown(MouseEventArgs e)
in System.Windows.Forms.Control.WmMouseDown(Messageamp m, MouseButtons button, Int32 clicks)

in System.Windows.Forms.Control.WndProc(Messageamp m)
in System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

Start by reproducing the shape-layer load in HydroDesktop 1.7.3 and inspect the stack trace entry at DotSpatial.Controls.Legend.HideEditBox(), called from Legend.OnMouseDown(). Done means loading and viewing the shape does not produce the reported NullReferenceException.

Written by the indexing model from the issue text.