Mark, you might try this:
- Open a page of all topics with
- Open, in another tab, the show all tags page
- Delete the existing
- Go back to #1, select all topics, and assign the new
BTW, I noticed something unusual. On the all tags page, some tags show up under the “Announcements” category. This might mean those tags were created for that category only. Unless you did that on purpose, you might want to delete those “Announcements” tags, and recreate them available to all categories.