Go to User directory > Library

There are two folders here to be concerned about:

Fonts

FontCollections

Create two folders on the desktop with these same names.  Move the contents of the font folders in the Library to the empty folders on the desktop.  Fonts and FontCollections in the user library should now be empty.

Log out of the user account.

Log back in to the user account.

Move the font files from the folders on the desktop back to their respective folders in User directory > Library.

Log out of the user account.

Log back in to the user account.

Relaunch DP. You should now see DP in its right form.