Assuming PS is Photoshop, you're in the wrong forum. Moving this to Photoshop general
you have not given us very much information, such as version of Photoshop, platform or operating system, but if it is Windows try going to
C:\Users\<profile name>\AppData\Roaming\Adobe\Adobe Photoshop CC 2017\CT Font Cache
and deleting the 'Font Cache' folder.