I noticed that now all of the link including “tags” in its URL does not work on my Discourse. Instead, “tag” is used. How can I change my old URLs set as a link automatically? There are many. So it’s totally impossible to change them manually. My Discourse us 2.9.0.beta4.
On my forums, which are very ordinary with no special setup, /tags/ has some kind of automatic redirect to /tag/. Note that I’m running the latest, 2.9.0.beta5 - I don’t know if this is something which changed. (It’s probably a good idea for you to update anyway.)
Edit: but see below! I now agree that there’s a problem.
Let’s pop in an example: 
https://meta.discourse.org/tags/getting-started
(though it doesn’t seem to like it when I wrap it in < > https://meta.discourse.org/tags/getting-started)
Ah, excellent example! So, indeed, while URLs for new requests (in the URL bar) get the redirection treatment, URLs from posts do not.
Can you move this to the bugs category? I think that’s justified.
I thought that inline onebox example worked, but then it didn’t, and then it did again. And it does if you refresh the ‘oops’ page as well. I’ve done a bit of digging and found this existing bug topic on what seems to be the same thing:
The OP in that report renamed their tags to get around the issue, though I’m not sure if they went the manual route or used Replace a string in all posts?
Thanks for digging my bug report up. I’m a mere moderator on our forums and have no access to the database to edit all impacted posts. The main concern was to keep that one very prominent post functional, as it links to dozens of tags. So, that was a manual job.
Thanks everyone.
If this is a bug and it remains as it is, I will change old URLs using “tags” to ones with “tag” manually.
However, I want to know whether Discourse uses “tag”, not “tags” from now on. If Discourse thinks using “tags” as it was is better, I won’t fix my links on my forum. If Discourse keeps using
“tag”, I have no choice but to fix everything manually by myself.
My concern is that there might be other Discourse users who set old “tags” URLS as a link. They might not notice this. If Discourse changes the current “tag” to the former “tags”, these users and I do not have to take care of this issue. What do you think? Should I post this in the bug category?
No need to repost - I’ve marked this topic and the previous bug report for some attention, and should hopeful have some information for you soon. 
OK. Meanwhile, I will leave disconnected links as they are.
I believe this has been fixed in:
I’ve just checked against the examples I posted above and it seems to be working much more consistently now without needing a page refresh. Could you try updating your Discourse and seeing if this solves the issue for you?
Thanks for your prompt improvement.
My forum uses 2.9.0.beta4. Should I update this to the latest 2.9.0.beta6?
It works well with 2.9.0 beta6. Thanks!