Obj Exporter stuck not continue when trying to export a object from unity. Why ?

I have a window that is part of a package. Not my package.
I selected it in the Hierarchy and then in the Exporter clicked on Export. The process got to 25% and stay on 25%.

What I want to do my main goal is export the window object to blender and then in blender to make on this window a breaking effect. I want to break the window to pieces.