This could be a serious problem. So far, I have already found this issue in two different courses, and I don’t even want to keep checking the other courses I have created because I am afraid of what I might find. If the audio cannot be recovered, it would mean losing a huge amount of work and many hours spent creating and recording these lessons.
This is much more serious than I initially thought. The problem seems to affect all lessons that were created manually, with the text added separately from the audio. Lessons imported directly from YouTube still work normally. This changes the situation completely, because I have hundreds of lessons created this way, and I imagine many other users may have the same problem. If these audio files cannot be recovered, it would mean losing a huge amount of work.
Update: I have just checked the LingQ Android app on my phone, and the audio actually works there. So the audio files themselves may still be intact. The problem seems to be specifically with the web version or the Edit mode, where LingQ says that the audio cannot be played.
This is still a serious issue because the audio works in the Android app but not on the website, and it affects many manually created lessons.