We've used Sourece Sans pro as our brand font for 5 years, and it was made available in our system drop down menus (Windows/PC users). Suddenly many employees including myself no longer have the font in their system or it is rendering with some other weird looking typeface, even though SSP is showing as the selected font. Our IT folks just reload it, but in my system it won't accept it and says does not recognize as a valid font. They are trying to troubleshoot, but we cannot seem to find an answer and more and more people are having problems. Existing files such as PPTs and communications are all looking out of whack. Any ideas what could be happening?