Find the problem

Start with the symptom you can see, then check the part of the setup responsible for it.

Before changing settings, note what works and what does not. A working website, a passing instance test, an accepted request, an imported file, and successful playback each prove a different step.

What you see	Start here
The app cannot open the server	Connections and addresses
An instance works in my browser but fails its test	Connections and addresses
Sign-in loops, a link expired, or SSO fails	Sign-in and access
Books, Music, a title, or a setting is missing	Missing tabs and content
A request stays Requested or Needs attention	Requests that do not progress
A transfer finishes but the title stays unavailable	Downloads and imports
Wrong episode, wrong audio, or a bad copy	Downloads and imports
A title is available but will not open or download	Playback and file downloads
A notification does not reach a phone or Discord	Notifications
The assistant cannot connect or a model fails	AI and MCP
Tdarr shows stale data or no workers	Tdarr progress
Apple TV discovery or title handoff fails	Apple TV setup

Read errors literally

No results means the specific search found nothing. Could not check means it could not establish the answer. Showing stale data means the last successful result is still displayed after a later failure.

Do not turn an unavailable check into a conclusion that the title, account, file, or download does not exist.

Gather a small useful example

Record the app and server versions from Settings > About, the affected service and instance, one exact title or request, the time, and the error text. Then follow the relevant guide.

For a Docker server, recent logs can help:

docker compose logs --since=15m --tail=200 cantinarr

Review logs before sharing them. Remove tokens, private URLs, usernames where unnecessary, and personal media details. Do not post your whole config folder or database.

If the guide does not resolve it, prepare a useful support report.