Error When Using MITMF

So I've been looking at launching MITM attacks, and started to play around when I discovered this problem

Command I typed

root@kali:~# echo 1 > /proc/sys/net/ipv4/ip_forward

root@kali:~# mitmf --arp --spoof --gateway 192.168.1.254 --target 192.168.1.74 -I wlan0

The attack now seemingly runs, however there is a problem.

Problem

When I try to access any website from the victim machine (192.168.1.74), I get a timeout error from the browser and eventually this message pops up in the terminal

Error message

"2017-05-18 19:20:41 ARPpoisoner Exception occurred while poisoning 192.168.1.74: Errno 100 Network is down"

Please advise as to what I am doing so badly wrong, many thanks :)