Evil Twin Attack Using Captive Portal

I am getting an error like this,
The interface wlan0 you already selected is not supporting vif(Virtual Interface). This attack needs it to virtually unfold itself to create a fake access point while also performing denial of Services(DoS). Do you want to continue? If yes denial of Service will not work being an important part an important part of the attack and making it probably ineffective[y/N]

Could anyone resolve this error?