Great, thank you! We ended up needing to set subject to be blank on the db directly then restarting.
We then saw some weird behaviour, for one of the two MUC rooms we had set-up, even though they both have exactly the same topic, it was still sending an xmpp message of group chat type, with the body as opening and closing subject tags with nothing in them (I used Spark to debug). In our XIFF client this actually caused XIFF to blow up.
We couldn't replicate it on any other environment, in the end we deleted and recreated the room and it worked. Not sure if it relates to this thread but have you ever seen that behaviour?
