It has been reported to us that in certain situations when clicking the Home tab after the RTM update, Word may throw the error message below indicating “There is insufficient memory or disk space. Word cannot display the requested font.”
We are aware of the issue and are actively investigating. We will be releasing a fix to Windows Update when the update has been tested and is ready for installation. In the mean time you should reboot your Windows RT device if you encounter this error. Rebooting will fix the problem permanently and will cause the fonts to be registered correctly.
Office Sustained Engineering