I get this error when launch lolnerod


Lolnero 'Hello World' (v0.4.0.0-release)
Initializing cryptonote protocol...
Cryptonote protocol initialized OK
Initializing core...
Loading blockchain from folder /home/xxx/.lolnero/lmdb ...
Loading checkpoints
Core initialized OK
Initializing p2p server...
Error starting server: Failed to bind IPv4 (set to required)
Deinitializing core...
Stopping cryptonote protocol...
Cryptonote protocol stopped successfully
Exception in main! Failed to initialize p2p server