docs: status pages

docs/reference/troubleshooting.md

@@ -160,6 +160,27 @@ needs `host`, `port`, `from` and `to`, and Telegram needs both `token` and
 | Instance degraded despite a valid-looking licence | It expired more than a few days ago. Pasting a new one still works, which is how you recover |
 | Cannot enrol another server                       | The server allowance is reached. Raise it in HQ or remove one                                                  |
 
+## A status page 404s or shows no data
+
+**404, and it should be published.** Check the **Published** toggle on the
+page's editor — an unpublished page answers *not found* for everyone,
+including you, with no session exemption. Also check the host: the public URL
+is `<your-instance>.vantage.<yourdomain>/status/<page-id>`, the same
+per-instance subdomain everything else in Vantage uses. A wrong or missing
+subdomain resolves to no instance at all, which is also a 404.
+
+**Loads, but shows an explanation instead of components.** This is not a
+fault — it is the page working as designed. It means either the licence has
+lapsed (a self-hosted instance past its grace period, or a cloud instance
+between billing events) or the current tier does not include the **Status
+pages** feature. Fix the licence or the plan and the same link starts serving
+data again with no republish needed.
+
+**One component reads `Unknown`.** The monitor behind it was deleted while
+still listed on the page. Nothing is checking it any more, so the page says so
+rather than showing a stale up or down. Remove the component from the page,
+or point it at a replacement monitor, in the page's editor.
+
 ## HQ portal problems
 
 The portal is a hosted service, so problems with it are ours to fix rather than