Have you tried this?
Having problems logging in? We highly recommend trying to clear your browser’s cookies and cache, if you are having problems using the new sign-in page.
How to clear cookies and cache in Firefox: Clear cookies and site data in Firefox | Firefox Help (mozilla.org)
How to reset Firefox: Refresh Firefox – reset add-ons and settings
How to clear cookies and cache in Edge: Delete cookies in Microsoft Edge – Microsoft Support
How to reset Edge: Resetting Microsoft Edge
How to clear cookies and cache in Chrome: Clear cache & cookies – Computer – Google Account Help
How to reset Chrome: Reset Chrome settings to default
Contact Servicedesk
Call us at +4546743600
Write to us at servicedesk@ruc.dk
Come by the Servicedesk in building 03.1-S. We are open all weekdays 08:00 – 16:00