1) A Fallback track plays every time the streamer loses connection to the server.
2) The file has to be of exactly the same bitrate and quality as your stream.
3) Select SETTINGS under CONFIGURATION section.
4) Select FILES tab.
5) Select/Open FALLBACK FILE.
6) Select prepared file and click OPEN.
7) Restart your server (Click RESTART in SERVER section).
8) If your listeners hear silence instead of the fallback file please make sure you have encoded it correctly (see point 2.).