CiviGroup Roles Sync errors
I don't think this is actually an 'error', the status is just misleading.

The Group &lt;> Role sync runs on a user when they log in, syncing up the roles. All this message is saying is: "When the user logged in, I added role x, because they are a member of group y."

The severity of these database log messages is misleading and will be fixed up in 4.7 by this commit: https://github.com/civicrm/civicrm-drupal/pull/272