local mp3 file "Error: Load failed"

[hfcheng66]

Installed on Ubuntu 18.04. Tried to play a local mp3 file:
$ castnow ./test.mp3 --address 192.168.2.xx
Error: Load failed

The TV connected with chromecast did show the name of mp3, but didn't play, a spinning icon displayed.

Firewall is inactive on the Ubuntu server.

Tested an online mp4 file, worked fine:
castnow http://commondatastorage.googleapis.com/gtv-videos-bucket/ED_1280.mp4 --address 192.168.2.xx

What could be the issue?

Thanks.

[nugged]

@hfcheng66 have you found the reason why?

[happyman]

@hfcheng66 try --myip option.