Attempting to login results in error page

When I attempt to login to the admin account - by either clicking the login link on the search page or the link in the admin page, I get this error page:

This site can’t be reached

The webpage at https://mysite/yacy/Status.html?login= might be temporarily down or it may have moved permanently to a new web address.


If I clear my browser cache, the problem is resolved, but then returns later on.

I am using the Vivaldi browser on Ubuntu, and Yacy is installed on a Debian server using YunoHost software for installation and management.