Whenever I attempt to start a MITM attack using ARP poisoning , the target machine receives
this error on chrome, IE and firefox.
This happens when attempting to spoof arp with mitmf, arpspoof and ettercap .

I have an open issue with MITMF git here https://github.com/byt3bl33d3r/MITMf/issues/216

When running
on target output shows that the gateway IP's mac reflects Kali's mac . I have also confirmed poisoning via wireshark.

I make sure that IP forwarding is set .

Although my iptables are blank? Can that be the issue? If so , what should iptables be set up as ?

I've been searching and reading, still cannot find out what's causing this issue.