Strange banned IP address issue

[chikuru]

vBulletin Message
Sorry. The administrator has banned your IP address. To contact the administrator click here

I am getting this all of a sudden.
I tried disabling plugins, using proxy(lots of proxy to change IP), and I still cant get inside the forum.
No users can login to the forum and getting this message..

[Dave]

Do you use a service such as Cloudflare or Incapsula? Try disabling it.
It's possible you have their IP addresses blocked in the vBulletin AdminCP > Settings > Options > User Banning Options.

If you completely can not access the forum because of that, open /includes/functions.php, look for the "verify_ip_ban" function and remove everything inside of it. If that also doesn't work then it has to be a plugin/script causing this.

[chikuru]

I am getting this after removing ban IP function

Fatal error: Call to undefined function verify_ip_ban() in /home/*********/public_html/forums/includes/class_bootstrap.php on line 910

[Dave]

Don't remove the whole function, remove what's in-between the opening and closing curly bracket.