The rosalind URL is an old one. We’ve migrated to medcat.sites.er.kcl.ac.uk for the most part.
However, the redirect has now stopped working as well.
You can use the demo just fine at medcat.sites.er.kcl.ac.uk. However, for the time being the model download link won’t work. The new authentication link (medcat.sites.er.kcl.ac.uk/auth-callback) needs to be registered manually. We’re working on this, but I’m not sure how long it will take exactly.