Hi @JuergenAuer,
"Advanced" says
'chub.gdslab.org normally uses encryption to protect your information. When Google Chrome tried to connect to chub.gdslab.org this time, the website sent back unusual and incorrect credentials. This may happen when an attacker is trying to pretend to be chub.gdslab.org, or a Wi-Fi sign-in screen has interrupted the connection. Your information is still secure because Google Chrome stopped the connection before any data was exchanged.
You cannot visit chub.gdslab.org right now because the website sent scrambled credentials that Google Chrome cannot process. Network errors and attacks are usually temporary, so this page will probably work later.'
This is the main URL. I believe the issue is because the technical department here has blocked accessing the page. I have submitted a request to whitelist the URL and I am waiting on their response.