we have a problem with a project that we are migrating .. use a webdialog to display information when you press a button on the grid, while we have a button that creates a new window on the desktop.
If you press the button on the grid and then press the button that creates the window, a javascript error "Error en tiempo de ejecución de JavaScript: No se puede obtener la propiedad 'Windows' de referencia nula o sin definir".

if only the button that creates window is pressed all is ok.. but when the button is pressed on the grid, this button stops working.
use internet explorer 11.

attached example.

steps to reproduce.

enter any username and password
press the  icon "incidencias"
Pressing the button "Ventana".
A new window appears with the login screen wil ..
close this window
Pressing the button on the grid "Activar"
a dialog appears.
close the dialog
again press the button "Ventana".
javascript error appears.

regards