Iam trying to parse fortigate syslog to logstash

when i run the command:
/usr/share/logstash/bin/logstash -f /etc/logstash/conf.d/fortigate.conf

I get the error :
udp - UDP listener died {:exception=>#<Errno::EADDRINUSE: Address already in use - bind(2) for "192.168.150.240" port 5041

here is my config:
input {
udp{
host => "192.168.150.240"
port => 5041
}

    }

filter {}

output {
stdout {}

}