Error with a font having a function . php

I updated recently and started seeing a problem whenever I edited a page.

This is the message that keeps popping up: https://i.imgur.com/9a0D9ow.png

Never had that issue before until after the update.
Wasn’t sure if I should just look for it and delete- but then I risk breaking something. So going to ask about it first before I do anything.

The page I need help with: [log in to see the link]