Problem with Admin username/password box

[dale1984]

Im on a brand new iMac which I got on Tuesday. I have this showing up and it's worrying me. Any ideas how I fix it??

 

[joelovesapple]

Did you accidentally remove any system fonts with third party apps such as Onyx?

 

[firedept]

Yep, looks like missing or corrupt font. Usually a good place to start looking.