is the test data * [test-envs-small-v3.0.tar.gz is down?
The download link is working fine.
We have expiry to links generated for download, just in case you are re-using older link. So please always download by opening link directly from the resources page here: https://www.aicrowd.com/challenges/flatland-challenge/dataset_files
Let us know in case it doesn’t work out for you.