submit_review_gtk3.py throws an exception

[Erik Zoltan]

I have a fresh Vivid 15.04 install on a System76 desktop computer. I turn on recommendations in Ubuntu Software Center and I expect to be able to write a review or rate a package I have installed. When I click the "write your own review" link, nothing happens. I am attempting to review the cream vim macros package, but I experience the same behavior if I try to review a different package.

Running software-center from the terminal, I see the following error message in the terminal window at the time that I click the "Write your own review" link.

(software-center:7441): Gtk-WARNING **: Unable to show 'none': Operation not supported
2015-06-05 02:07:00,033 - softwarecenter.backend.spawn_helper - WARNING - exit code 1 from helper for '['/usr/share/software-center/submit_review_gtk3.py', '--pkgname', 'cream', '--iconname', '', '--parent-xid', '', '--version', '0.43-3', '--origin', 'ubuntu', '--datadir', '/usr/share/software-center/']'
2015-06-05 02:07:00,033 - softwarecenter.backend.spawn_helper - WARNING - got error from helper: 'Traceback (most recent call last):
  File "/usr/share/software-center/submit_review_gtk3.py", line 117, in <module>
    version=options.version)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/review_gui_helper.py", line 595, in __init__
    BaseApp.__init__(self, datadir, "submit_review.ui")
  File "/usr/share/software-center/softwarecenter/ui/gtk3/review_gui_helper.py", line 382, in __init__
    self, os.path.join(datadir, "ui/gtk3", uifile), "software-center")
  File "/usr/share/software-center/softwarecenter/ui/gtk3/SimpleGtkbuilderApp.py", line 32, in __init__
    self.builder.add_from_file(path)
GLib.Error: gtk-builder-error-quark: Invalid property: GtkGrid.n_rows on line 409 (11)
'
/usr/bin/software-center:184: Warning: Source ID 2975 was not found when attempting to remove it
  Gtk.main()

I am using Ubuntu 15.04.
The installed version of software-center is 13.10-0ubuntu6
Happy to provide additional information if it will help.