Screen problem on a Mac Book Pro Retina 13"

Hello,
I've got a strange bug on my Mac Book Pro Retina 13". 

When I talk to someone in the game, I can't read all the text. The window with the text is bigger than my screen and there is no way to reduce it. 

Screen capture here :  http://imageshack.com/a/img907/7448/e93MBL.jpg

I didn't had this problem before and now I can't fix it. 

I've tried all the changes possible in the graphical panel but nothing is working. 

Thanks for your help. 

Gilles

MacBook Pro (Retina, 13-inch, Late 2013)

2,6 GHz Intel Core i5

16 Go 1600 MHz DDR3

Yosemite - 10.10.2

Edited April 2, 201510 yr by gilloux69