Cannot type in name!

So, I was using the different color codes when suddenly The underscore _ disappeared when I was typing, Now I can no longer have a name and I cant join servers because of it. I have a picture of my settings with no name...
It only appears to work on 0.11.0 because of the new colors but I haven't updated to 0.11.1 yet because it doesn't say anything about color idk...