This is a first-day-of-use error message that will appear as a warning triangle at the top of your PandoraFMS v4 Administration Console. The fix is easy. Go into the menu option,

Administration -> Setup -> Visual Styles

and set the  Fontpath option (it will be set but not saved into the new
database schema) and then do an Update on that page just the once.

That clears that warning triangle message. If you didn’t notice then the warning triangle appears at the top near your username and logout icon.