Can't use certain tags to tag topics anymore


We are using about 20 or so different tags on our site (which all show up and work on /tags), but for some reason only some tags autocomplete when typing into tagging box for topics.

Ok, so we thought maybe the autocomplete on the tag search isn’t working, so we manually type the tag (which should work even if the tag doesn’t exist) and hit save, but the tag just disappears right away after saving, and checking the revisions shows:

tags changed: [] → 

All the tags do seem to be POSTing correctly, and I even tried directly with the API, but only the existing tags that autocomplete and new tags will stick, while the existing tags that don’t autocomplete just disappear without any errors.

The weird thing is that hash-tags within posts still works perfectly (autocomplete and everything) for all our tags, so it’s just something wrong on the topic tags.

Any help would be appreciated.

Edit: Just noticed that these “missing tags” are also absent from that tag filter dropdown.

Also noticed that all of these tags have been used over 900 times.


Did you configure some tags on the category ? (Edit > Tags > Tags that can only be used in this category)

If you don’t add a certain tag, it won’t be admitted on the topic and autocomplete won’t work


Nope, never added anything there, and everything was working fine till yesterday.

However, just added some of the missing tags to a category and they’re showing up now.

Thanks for the idea!

(Thomas Huulbæk Titanium) #4

I experience the same bug - also not using category specific tags.

(Thorben Egberts) #5

We are experiencing that if we save the “Tags that can only be used in this category” setting empty, many, but not all tags show up in this settings. After saving again, this leads to problems that some tags can’t be used in other categories :frowning:

(Sam Saffron) #6

@neil can have a look on your site, since you are hosted by us, what is the exact example?

(Thomas Huulbæk Titanium) #11

Yes, this is the scenario. The tedious workaround we use right now:

  1. Go to category and add the problematic tag to the allowed list for this category.
  2. Tag the post.
  3. Remove the tag from allowed list again.
  4. Repeat for other category.

The problem occurred after experimenting with setting the tag in the allowed list for a category in the first place and removing it again.

(Neil Lalonde) #12

I updated your site ( so please try now to see if your problem is fixed. You were missing some important fixes for tag settings and inputs (1, 2, 3, others…).

(Thomas Huulbæk Titanium) #13

I am on latest Discourse and this is how it looks on our end:

The tag appears briefly and then disappears.


Exactly the same case here.
Version: v1.6.0.beta12 +76


(Sam Saffron) #15

Interesting, I can’t make this happen on meta, but if its happening on plentymarkets we @neil should be able to debug.


Hello Sam.

Here, all the categories have been set with “tags” configuration?
Try to edit one, and remove all “tag’s groups” from that.

I’ve been testing about this, and if I set tag’s groups, and then edit each category with some groups, the tags does not disappear. :slight_smile:

(Neil Lalonde) #17

I can’t follow what people are talking about here. I need to see your category settings (screenshots) and how you create the topics and what happens.

(Neil Lalonde) #18

I fixed something confusing about the UI that might be what you’re describing.

  • A tag “ford” is restricted to be used in a category.
  • In a different category, try to add the “ford” tag.
  • Someone who is allowed to create new tags sees this, and you can add “ford” to the tags input:

  • Someone who is not allowed to create new tags sees this, and can’t add “ford”:

The second case is correct since no one should be able to add that tag in the wrong category.

Adding tag to two or more groups breaks the tag

Neil, remember when don’t exist tag’s groups?
You go to a topic, edit and add some tag.

With new version, and this feature (groups of tags), if you did the last action, discouse works like @huulbaek said here (there is a gif-screenshots).

He means that the tag disappear instead save it.

(Thomas Huulbæk Titanium) #20


It turned out that I was mistaken. Another admin on our site had added the tag in question to another category that was not checked by me upon investigation. So many categories on our site but I found it via the Data Explorer:

SELECT category_id FROM category_tags


(Jeff Atwood) #21