Can't load reportserver in browser We are running SQL Server 2016 and cannot view the list of reports in the browser when we go to http://servername/reportserver. When we go to that link in the browser, it asks for credentials. When I've used my own, it simply gives me the credentials pop-up again with no error. This repeats until the browser gives an HTTP 400 error. When I try the sa credentials, I only have to do it once but it still gives the HTTP 400 error. I can connect to the server in SSMS and can even query the Catalog table from the database. I can also save reports onto the server using Report Builder.
The issue is most likely that you haven't configured your Service Principal Names for the Report Server, so it is encountering an error trying to utilise Kerberos Authentication.
Firstly, you need to confirm your SPNs are configured correctly for the Report Server. You can use Kerberos Configuration Manager for SQL Server to identify any issues with your SPNs and fix those issues.
Once your SPNs are corrected, add the address (http://servername/) to your trusted sites to enable your Windows identity to be passed through automatically and facilitate SSO.