Message: A problem occurred when installing or de-installing a font

Cause

You have tried to install a font
that is already installed, or you have tried to de-install a font that is currently being used in a document. It is also possible the font file itself is corrupt.

What Can I Do?

Installing a font - check that it isn't installed already.

De-installing a font - make sure it isn't being used in any loaded documents.

If these do not apply, it is likely the font file is corrupt. You need to reinstall the font from a backup using the Fonts section of Control Panel.