I have a rather basic question about a simple action: how do I create a new text style in Autocad for Mac?!

I know how I should do it, but when I get the text style dialog box and click the "+" under the text style list on the left, NOTHING happens.

What am I missing here?

@jodecaesteker, 
john.vellek has edited your subject line for clarity:Can not create a new text style?!!!