Please try the following
1) Re-validate files on Steam, this could actually be an issue
-Right click on Dawn of Fantasy in your Steam Library, and go to Game Properties
-In Game properties click on Local Files, and select Re-validate game files.
2) Install the game using our own client: http://dof.reverieworld.com/download.php
You can keep your Steam installation as is, no problem there with having both.
3) Download and Install this font on your Windows: http://www.fontpalace.com/font-download/Trebuchet+MS/