MP4 import opens empty

Audacity was working in former releases. Now when I convert an mp4 to get the audio there is no audio jus a flat line. The FF converter seems to be working. I can open and watch the mp4 with other software so I know it downloaded correctly. I have uninstalled old versions and installed 3.1 3 times As well as the FF converter.

Try converting the files to WAV with [u]Kabuu Audio converter[/u].