Frontail not start error : throw er; // Unhandled 'error' event

Hello i m using frontail on ubuntu 18.04 LTS and i got this error : what do u think is wrong please :

Issa@srv:~$ frontail /var/log/syslog
events.js:183
      throw er; // Unhandled 'error' event
      ^

Error: listen EADDRINUSE 0.0.0.0:9001
    at Object._errnoException (util.js:1022:11)
    at _exceptionWithHostPort (util.js:1044:20)
    at Server.setupListenHandle [as _listen2] (net.js:1367:14)
    at listenInCluster (net.js:1408:12)
    at doListen (net.js:1517:7)
    at _combinedTickCallback (internal/process/next_tick.js:141:11)
    at process._tickCallback (internal/process/next_tick.js:180:9)
    at Function.Module.runMain (module.js:695:11)
    at startup (bootstrap_node.js:188:16)
    at bootstrap_node.js:609:3

mthenw / frontail

Frontail not start error : throw er; // Unhandled 'error' event #218