While trying to run Bless (the hex editor), mono will try to install a font with the message:

mono wants to install a font
An additional font is required to view this document correctly.
Language code not matched: utf-8

If the package manager is unable to find the right font (which is the case for me), install the following manually to resolve the issue:

xorg-x11-fonts-ISO8859-1-100dpi.noarch 0:7.2-9.1.el6                          
xorg-x11-fonts-ISO8859-1-75dpi.noarch 0:7.2-9.1.el6                           
xorg-x11-fonts-misc.noarch 0:7.2-9.1.el6    
dejavu-lgc-sans-fonts