Hello,
I encountered his problem while using metasploit .. actually I have Kali installed on hard disk version x64 normally I don't have network problems but it's the frist time I see this issue and i don't know how to deal with it !
message :
msf auxiliary(syn) > run
/opt/metasploit/apps/pro/msf3/lib/msf/core/exploit/capture.rb:122: warning: unable to get IP: eth0: no IPv4 address assigned
/opt/metasploit/apps/pro/msf3/modules/auxiliary/scanner/portscan/syn.rb:61: warning: unable to get IP: eth0: no IPv4 address assigned
[*] Cannot stat device: eth0: no IPv4 address assigned
[-] Error: RuntimeError Pcaprub error: eth0: no IPv4 address assigned
/opt/metasploit/apps/pro/msf3/modules/auxiliary/scanner/portscan/syn.rb:61: warning: unable to get IP: eth0: no IPv4 address assigned[*] Cannot stat device: eth0: no IPv4 address assigned
[-] Error: RuntimeError Pcaprub error: eth0: no IPv4 address assigned
/opt/metasploit/apps/pro/msf3/modules/auxiliary/scanner/portscan/syn.rb:61: warning: unable to get IP: eth0: no IPv4 address assigned

thanks in advance for help