Live captions aren’t appearing

No captions at all

Is the session actually live? The console shows this — press Go live if not.
Is audio reaching the console? Speak and watch for movement on the input.
Is the right input selected? A laptop that switched to its built-in microphone when something was unplugged is the classic cause.
Is the machine online? Captioning needs a live internet connection throughout.
Did the session end itself? After 10 minutes without audio it ends automatically — the console warns first with “No audio for … minutes”. Press Go live to start again.
Does the console show Upgrade Live Translation where Go live should be? Your translation hours for the period are used up; if they run out mid-service the session ends on its own.
Does the console show Mic muted or Captions hidden? Someone muted the input or hid the captions — switch it back on the console.
More fixes for the console itself are in Fix a Live Translation session that is not working.

Poor audio. Distant microphones, room echo and a noisy hall all produce exactly this. A feed from the sound desk fixes it; nothing in the settings will.
Wrong spoken language. If the system thinks it is hearing a different language, output is nonsense — see Choose translation languages.
Unusual names and words. These can be taught in advance under Settings → Captions → Custom vocabulary, and are worth doing for the ones your church uses every week.

Is the session live? Nothing appears on a guest’s phone until it is.
Are they on the current link? The guest link stays the same every week unless someone pressed Regenerate — after that, old links and printed QR codes show “This caption link isn’t available”.
Are they reading the language they expect? The caption page picks one for them — their last choice, the link’s language, or their phone’s — and they can change it by tapping the language name on the page.
Does the phone say “This service is full”? The service has reached its listener limit; the page joins by itself when a place frees up.
Is the venue’s wifi coping? Two hundred phones on one access point is its own problem.
For what each message on a guest’s phone means, see Read live captions on your phone.

Was the overlay link added as a web item (a browser source, a web object, a website item)? The captions feature built into presentation software connects to a different service and stays blank whatever link is pasted into it.
Add &preview=1 to the end of the link while testing. A status box then says whether the link is accepted, whether a session is running and whether captions are arriving.
Does the web item cover the whole slide? A short item cuts rows off the bottom.
A link shows only the language it was made with. If the service is not producing that language — or someone pressed Regenerate on the overlay link — the screen stays blank. The &preview=1 status box, or the Test button on the Overlay link card, tells you which.
The per-program steps are in Show captions on a screen or in your video mixer.