For some reason I'm unable to edit my characters theme, background, and background benefit. They are all greyed out. I've done it before on a previous character. The character I'm trying to make is a tiefling wizard (mage) of the enchantment school. The previous character that I was able to edit the theme and background of was a drow rogue (nightstalker). If that makes any difference, I really don't know. I just want to be able to edit the theme mainly 
p.s this is using the 4e character builder
We don't have that problem here in 5e, because we don't have a character builder. 
You could try the DD Insider forum