Can't post an avatar no matter what I do

Muttt

Sergeant
Full Member
Minuteman
I've been trying to post an avatar to my profile but it just won't work. At first it kept telling me UBB error wrong file type. But, I dropped my pixels all the way down to 50 x 50 and I'm using a jpg, but I still can't get it to work. I've tried posting it on photobucket and loading that way. I've tried loading from my computer .... no joy. What am I doing wrong????