I have an ‘undefined’ category stuck in users preferences:
When i try to delete it, it just scrolls to the top of the page. This is also locking any other changes on the user. eg. changing their long name after hitting save, the page just loads forever and the changes do not apply.
This would appear to have happened after the category which was previously watched was deleted. I tried re-creating the topic to no avail.
On user accounts who had not ‘watched’ this topic, everything is working fine.