Hello,
This error usually happens because you have a corrupt font on your computer or you have too many fonts and you memory just can't handle it.
Try this:
Re-create the Photoshop preferences file to eliminate problems that a damaged preferences file might cause.
Note: When you use this solution, Photoshop will create a new preferences file and you will lose custom settings associated with your current preferences file. However, the file you rename in step 2 is your original preferences file. If you determine that the preferences file is not causing the problem, then you can restore your custom settings by following the instructions below.
To re-create the Photoshop preferences file:
Quit Photoshop.
Rename the Adobe Photoshop CS4 Prefs.psp file (for example, to Adobe Photoshop CS4 Prefs.psp.old) in the Documents and Settings/[username]/Application Data/Adobe/Adobe Photoshop CS4/Adobe Photoshop CS4 Settings folder.
Start Photoshop. Photoshop creates a new preferences file.
P.S: This is for CS4 but this works at any version.