To take advantage of the new rendering engine that Windows utilises these fonts are no longer supported in Office 2013:

• Bitmap
• Printer
• Adobe Type 1
• CFF/Type 2
• TTO
• .FON

If you currently rely on one of these types of Fonts then you may want to visit http://www.freefontconverter.com and try converting them to another Font Type such as TTF (TrueType Font)