myschools.nyc Additional Materials upload error?

I'm uploading JPGs and MP4s to myschools.nyc for Additional Materials for Visual Arts, and I'm consistently getting an error ("failed attempt") message. I've tried both Chrome and Firefox, as well as on a Macbook and PC. I have also converted some of my files to PNGs and PDFs at some point. And have even simplified my file naming. Basically trying to remove any user error.

Is anyone else having similar issues? Getting close to December 4th deadline and I have to believe others are uploading this Thanksgiving weekend. Thanks!