HELP!!!!!!111 URGENT!!!!!11

HELP! My custom made 28-105mm f/2.8-3.8 lens says error 99 when I try to take a picture... WHAT TO DO???????????????''''' :hail:

 

Hmm make sure it is at the smallest aperture.

 

turn the camera off. remove the lens. put the lens back on. turn the camera back on.

 

Ask the people that custom made it?

 

thanks people! The first comment worked... I forgot to put it on 2.8... Silly me ... Thanks!