Server Autopwn Not Working for Me

Using this exploit labelled as excelent ..doesnt work for me though neither LAN or WAN , does not matter.

In WAN i use lhost as public IP and SRVHOST as internal IP ...when i launch the attack it says handler failed to "public ip"

i have checked lsof -i:8080 and only the process is listening nothing else. Yes i have port forwarded 8080

thanks