To correctly set up the emulator on Windows or Android, you must download and install two distinct official files: the main firmware PSVUPDAT.PUP firmware font package PSP2UPDAT.PUP

: The font package ( PSP2UPDAT.PUP ) contains the official system fonts used for text in menus and in-game overlays. Without it, many games may crash or display unreadable text. Official Download and Installation Guide

One of the font files is corrupted. Delete the entire fonts folder and re-extract the exclusive package. Also, ensure you aren't mixing fonts from firmware 3.60 with firmware 3.74 – they are incompatible.