Good afternoon.
This problem is not related to our system, it is the configuration of the Web service server and protocols.
On your server, the https protocol is not configured and the SSL certificate is not installed.
Browser content policies have changed and the browser itself decides which protocol will be used to connect to the site. The browser selects the https protocol, but on the server where the system is located, the SSL certificate is not installed and this protocol is not enabled, so you get an error.
You can try clearing your browser history and cache and connect using
http://tehresurs.crm-onebox.com/in private browsing mode, in Firefox it's "New Private Window".
You can also install an SSL certificate on the domain and then everything will be fine.