SQL Reporting Services. HTTP Error 503 The service is unavailable

After I installed new certificate using SQL RS Configuration Manager upon opening any report I see the following:

In comparison to this case the root cause is the same: when binding a certificate Configuration Manager creates shitty URL bindings like

https://+:443/ReportServer

https://+:443/Reports/

which is registered inside of http.sys. Report Manager cannot find this URL to authenticate, and hence you’ll get your error. This same thing holds true for many types of other scenarios where Report Manager is not able to communicate with Report Server.

• Remove the previous URL reservations from http.sys.
  • Open an Admin Command Prompt, and type in the netsh commands to show the URL reservations, and then delete them:
  • netsh http show urlacl
  • netsh http delete urlacl url="https://+:443/ReportServer/"
  • netsh http delete urlacl url="https://+:443/Reports/"
• Add the URL of your Report Server:
  • Open an Admin Command Prompt, and type in the netsh commands to add your URLs using the domain/username of your Reporting Services Service Account found in the Reporting Services Configuration Manager:
  • netsh http add urlacl url="https://mysitename.contoso.com:443/Reports" user=Domain\user
  • netsh http add urlacl url="https://mysitename.contoso.com:443/ReportServer" user=Domain\user
• Once that is done, replace the FQDN for the URL Reservation inside of your rsreportserver.config file to match, found here: <Program Files>\Microsoft SQL Server\MSRSXX.MSSQLSERVER\Reporting Services\ReportServer

• Restart Reporting Services inside of the Report Server Configuration Manager, and now your Report Manager site should come up.

Good luck!