SSMS 2014 Gives an exception when opening the new query window
This issue has been posted as a Microsoft Connect item.

2012 SSMS System.Windows.Media.Fonts Exception On New Query  

A possible workaround was posted by the author as follows:


  I have found that if change the font for the "Text Editor" from the default of "Consolas" to something else (e.g. Lucida Console), this problem goes away.