An episode marked Needs attention shows what happened and a Try again button.
The messages
"Transcription failed. Try again in a few minutes." Your credits were given back. Trying again charges the episode's credits once more.
"No speech was found in this episode." Check the file has spoken audio, then upload the right file.
"Writing the episode notes failed. Try again; it costs nothing." The transcript is safe. Trying again only rewrites the notes.
What to do
Tap Try again on the episode page. You can leave the page while it works.
If the episode file was deleted from Assets, you see "The episode file was deleted. Upload it again." Upload the episode again as a new episode.