Sony still holds the copyright for the firmware and fonts. While the emulator is legal, distributing the firmware file is a gray area. Always verify the MD5 hash of your .pup file against official Sony update logs if possible.
This is the step most guides miss. Open config.yml in Notepad. Find the line: current-font-package: Change it to: current-font-package: "data/font/" vita3k firmware font package download new
Test
The Vita3K emulator does not come with Sony’s proprietary files. You must download them separately from official sources: Official Firmware (PSVUPDAT.PUP): Sony still holds the copyright for the firmware and fonts