I get a 404
Just tested, works fine with Safari (mobile, but desktop usually has the same behavior).
Chrome's attempt to use a secure connection resulting in 404 while the actual link works fine isn't great. But it's understandable and the TLS-first assumption the're using probably works just fine in the other 99.999% situations.
If only they'd taken the time to copy the http config and setup let's encrypt or cert from GEANT Vereniging CA apparently preferred by rug.nl...