Look at your database and at the table GDN_Permission. Delete the column Plugins.Tagging.Add Make sure the permissions are sti correct for the tagging feature afterwards
@TheSage That looks like it might be related to the Tagging plugin, which was added into the core since 2.1 See the comment here and following: https://open.vanillaforums.com/discussion/comment/258969/#Comment_258969
Ok, it seems I got it working by dropping the Plugins.Tagging.Add column in GDN_Permission. Still kinda curious why it decided to break now, since tagging moved to core somewhere around 2.5 - 2.6.
@whu606 No column labeled Plugins.Tagging.Add in the database nor do I have the stand alone tagging plugin. I also searched for t.FullName in the databases and in the class.database.php without luck... Where do I head next?
Looks like I ran into a fatal error when running /utility/update too. I did install php-intl before the update like some people mentioned, but this is obviously something different. Installation is old enough (started on 2.3, I think) to have used Tagging as a plugin before it got integrated in the Core, so I'm guessing…