Audacity suddenly reports "malformed MP3" but file play perfectly under Mac's Music

As in the subject line: I have an MP3 file which plays perfectly in Mac’s Music utility but won’t load into Audacity: I get the message Import failed. This is likely caused by a malformed MP3.

The curious thing is that two days ago the file loaded and played with no problems at all. I’ve changed nothing since then, with the sole exception of plugging in a portable USB twin-speaker unit and setting Audacity’s output to USBAudio2.0. As a test I reset Audacity’s output to the laptop’s internal speakers, but the file still refused to load.

Can anyone suggest what might have happened? I’m using a MacBook Air running Catalina 10.15.7 and Audacity 3.0.2. Many thanks.

I’m a Windows guy so I don’t know what application to use, but usually the easiest fix is to convert it to WAV with another application. (Audacity will decompress it to PCM when you open it anyway.) Then you can open the WAV in Audacity and re-export as MP3 after editing, if that’s what you want. The new MP3 will be OK.

I’ve changed nothing since then, with the sole exception of

I can’t explain that, but at one time Audacity wasn’t so “picky” and it would open an MP4/M4A file if it was mis-named “MP3” but of course it wouldn’t work properly and you’d just get noise and you wouldn’t know why. They made it more strict and then all of these “imperfect” MP3s started showing-up. So, I think they’ve eased-up a little but it’s still checking the MP3 and it’s still more picky than most other applications.

Thanks for the suggestions; I’ll investigate. Whether or not converting it to WAV and back again works, what’s really puzzling me is that the file used to play flawlessly and now doesn’t. Very strange.

Which version of Audacity are you using? Recently Audacity was made more picky about malformed MP3 files (some of these errors in the file structure did not affect playback). With the latest (3.1.3) version this has been relaxed somewhat.

A good Mac utility for converting audio files between formats is Max.

– Bill

There is a known issue logged for this in GitHub

Audacity doesn’t recognize a mp3 file even though it’s a mp3 file. #2634


Thanks for the new replies.

Billw58, I’m using Audacity 3.0.2; maybe I should update to the latest version.

Waxcylinder, thanks for the link; I’ll take a look.