Can't import mp4 video on different account [SOLVED]

I have followed all the instructions, downloaded the FFmpeg file AND Audacity has successfully located it through the window in Preferences, and yes, it now is followed by a number there. So it is properly installed according to your instructions. BUT when trying to import audio from an mp4 video I still get the same error message that tells me to do all the above. It says this is an “Advanced Audio Code” file that Audacity can’t import; to do so I need to convert it to WAV or AIFF and I can do this with the FFmpeg. . . and so forth. It is a never-ending circle. Can you tell me how to get out of it and convert the mp4 video to an audio format that Audacity can read?

Check that you are using Audacity 2.0.5 (look in “Audacity > About Audacity”).
Audacity 2.0.5 is available here:

If you are using the current version (2.0.5) and the problem persists, check that FFmpeg is working:

  1. Record, import or generate some audio.
  2. Export in one of the FFmpeg supported format (for example AAC)
  3. Import the file that you exported in (2).

What sort of Mac are you using? What operating system?

Thanks for those suggestions:
I am already using Audacity 2.0.5
I have tried what you suggest (export/import with FFmpeg) and yes, it works fine with a exported exported in AAC
I am using a MacBook, about 4 years old, with Mac OS 10.8.5

Does that offer any more clues?

Yes it does.
The good news is that your set-up appears to be correct and fully functional.
The bad news is that that particular MP4 video appears to either be corrupt, copy protected (DRM) or an unsupported format.

Are you able to play that file in other programs?
What does QuickTime tell you about the format of that file?

OK, I’ve solved the problem: it was an Apple problem, not an Audacity problem. The file was downloaded in a different account on the same computer. For “some reason” Mac OS locks files like this when transferred from one user account to another–which makes using separate accounts on your own computer (for example for work and home) very annoying. . . I was able to import into Audacity normally once I attempted to do so in the account where the file was downloaded. Sorry to have bothered you about this–and thanks for the help!