I want to upload my school contest scoreboard to the gym.

We use domjudge for the contest and use DOMjudge-to-CFgym.py to generate the DAT-file.

I've been using this method to upload the scoreboard for a long time, but this time it failed to upload (run out of the error page with the picture below).

I tried several times and tried different scoreboards but failed. Is this a bug or how to solve it?