The issue of missing tag counts on the /tags page has been reported by salbertelli. After some investigation, JammyDodger suggested checking the include secure categories in tag counts admin setting, but salbertelli found that enabling this setting did not resolve the issue.
Akshine then debugged the issue and discovered that the problem is likely due to the pmCount being undefined, causing the totalCount to have a NaN value. This issue was fixed in a PR that landed in Discourse version 3.1.0. Since the site is currently running on version 3.0.6, Arkshine recommends updating to the latest stable version, at least 3.1.0, to resolve the issue. salbertelli has thanked Arkshine for their debugging skills and will follow up with their server admin to schedule the upgrade.
I’ve recently observed that the tag counts (e.g., “Java X 10”) are no longer visible on our /tags page. Instead, we only see a list of tags without their respective counts.
Any insights on what might be causing this sudden disappearance of counts would be greatly appreciated. Thank you!
My guess would be you have theme that removes it. I don’t see the problem on Meta or any of the sites I regularly use.
If you have a chunk of private categories it could be the include secure categories in tag counts admin setting?
Hi Jon, Thank you for your reply. Unfortunately, I haven’t introduced any new themes.
Hi JammyDodger! I do have a chunk of private categories. I will have a look at that setting. Ty!
The ‘include secure categories in tag counts` admin setting was disabled. I enabled it, but unfortunately no luck in showing the tag counts.
Strange.
I found the site on another topic and checked it without plugins/themes, but the issue still happens.
What is odd is the count in the API.
Looking at the source code:
I tried to debug to see, and the count is well passed. It is; no problem here.
However, we can see the pmCount is undefined. This is likely the issue because the totalCount has a NaN (Not A Number) value now, which is why the condition in the template is ignoring it.
Looking at the GIT history, this function has been fixed in this PR where you can see pmCount is being checked before adding the two numbers.
SECURITY: Hide PM count for tags by default (#20061) · discourse/discourse@f31f0b7 · GitHub
This fix is available since 3.1.0.
Searching your Discourse version gives me you’re using an old stable version 3.0.6
Short version:
You’re using Discourse 3.0.6, and a fix landed in 3.1.0, which fixed indirectly this issue. 
You can probably fix your issue by updating to the latest stable version, which is 3.2.0 or, at the very least, 3.1.0.
Fantastic! Many thanks, Arkshine! I appreciate your time, and superb debugging skills are greatly valued in pinpointing the root cause.
I will follow up with our server admin regarding the upgrade.
