Traceback (most recent call last):
  File "/usr/share/software-center/softwarecenter/ui/gtk3/widgets/recommendations.py", line 121, in _on_opt_in_button_clicked
    self._upload_user_profile_and_get_recommendations()
  File "/usr/share/software-center/softwarecenter/ui/gtk3/widgets/recommendations.py", line 125, in _upload_user_profile_and_get_recommendations
    self._upload_user_profile()
  File "/usr/share/software-center/softwarecenter/ui/gtk3/widgets/recommendations.py", line 133, in _upload_user_profile
    self.recommender_agent.post_submit_profile(self.catview.db)
  File "/usr/share/software-center/softwarecenter/backend/recagent.py", line 100, in post_submit_profile
    for app in get_installed_apps_list(db)]
  File "/usr/share/software-center/softwarecenter/db/utils.py", line 36, in get_installed_apps_list
    for doc in db:
  File "/usr/share/software-center/softwarecenter/db/database.py", line 525, in __iter__
    for it in self.xapiandb.postlist(""):
  File "/usr/lib/python2.7/dist-packages/xapian/__init__.py", line 7178, in next
    return PostingItem(self)
  File "/usr/lib/python2.7/dist-packages/xapian/__init__.py", line 7105, in __init__
    self.doclength = iter._iter.get_doclength()
DatabaseModifiedError: The revision being read has been discarded - you should call Xapian::Database::reopen() and retry the operation