Web Interface Issue

This morning I started running my evostream mediaserver for some testing purposes. The server seems to have started correctly and it responds correctly to API-calls. When I open the web-interface, I get prompted for the login credentials. I never changed the login credentials, so these are “evostream” and the instance-ID of my EC2 instance. Though when these are entered, I get refused with the message “Your connection to this site is not private”.. I checked different browsers, emptied all history and cookies and rebooted the server, but so far nothing seems to have helped. Do you have an idea why this is happening?