Two weeks ago was the last time I was able to do this.
For at least two years now, I’ve been able to import a fresh mp2 file as the meat of a vignette. Now, I can’t even import the same file I used two weeks ago. Audacity version 2.4.2. Still will not import even after a fresh install last week.
Do you have [u]FFmpeg[/u] installed? If you upgraded from an older version of Audacity you may need to upgrade FFmpeg.
Do you have something that can play the file?
If you have FFmpeg installed and you still can’t open it, check the file format/details with [u]MediaInfoOnline[/u] and post the results here.