The report server cannot open a connection to the report server database. A connection to the database is required for all requests and processing. (rsReportServerDatabaseUnavailable) Get Online Help

You might receive this error when you try to open the Report Server Manager.

"The report server cannot open a connection to the report server database. A connection to the database is required for all requests and processing. (rsReportServerDatabaseUnavailable) Get Online Help" A screenshot below of error

The error indicates that the report server GUI is not able to connect to the report server database. There are various scenerios under this can happen. To resolve this issue you need to point you Reporting Server database to correct SQL Server instance where databases are hosted.

I will write a post on how to configure/point reporting databases in my next article.