Photoshop crashing when exporting an mp4 as a gif using savoe for web

I have an employee who is attempting to export a 10-second mp4 file as a GIF using the save for web (legacy) option but it keeps crashing. We have tried reverting to previous Photoshop versions to no avail. The file is a 1080 x 1080p video and this is required for our website. They are on a Macbook Pro running MacOS 14.1 Sonoma and have tried Photoshop, Photoshop Beta, and their previous versions. They said they have done this before without it causing any issues.