You can only upload tracks that are either .mp3 or .m4a audio format to your Live365 library. 

The files should be encoded at 128 kbps and 44.1 kHz sample rate. Also, be sure the channel mode is "Joint Stereo" and the bit rate mode is "constant" (CBR), not "variable" (VBR). 

Live365 can handle lower bit rates, but higher ones are not supported at this time.