All Tracks Silenced While Editing

Windows 8.1, Audacity version 2.0.6

As I was editing a project with multiple tracks, all of them became silenced, and can’t be undone. I thought it was just a sort of option like muting tracks, but I can’t find it if it is. I exported the project into mp3, to see if the sound would returned, but it did not. Any ideas?

all of them became silenced

When you did what? Where were you in the editing process? How many tracks and how long? What was the show?

Koz

The current version of Audacity is 2.1.1 and is available here: http://web.audacityteam.org/download/

Were they tracks that you recorded in Audacity, or Imported files?
If they were imported files, were they WAV files?
If they were imported WAV files, have you moved, reamed or deleted the original files?