Remove failing mirrors
Working on #22182 (moved) the updated script reported several issues with currently listed mirrors. They should be removed (by running the script with --remove-failing) if the errors turn out to be permanent.
Instructions for configuring a mirror: https://www.torproject.org/docs/running-a-mirror.html.en
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information