This error occurs when the report server cannot connect to the SQL Server relational database that provides internal storage to the server. The connection to the report server database is managed
through the Reporting Services Configuration tool. You can run the tool, go to the Database Setup page, and correct the connection information. Using the tool to update connection information is a best practice; the tool ensures that dependent settings are
updated and that services are restarted. For more information, see Configuring a Report Server Database Connection and Configuring
the Report Server Service Account.
This error can also occur if the Database Engine instance that hosts the report server database is not configured for remote connections. Remote connection is enabled by default in some editions
of SQL Server. To verify whether it is enabled on the SQL Server Database Engine instance you are using, run the SQL Server Configuration Manager tool. You must enable both TCP/IP and named pipes. A report server uses both protocols. For instructions
on how to enable remote connections, see the section "How to Configure Remote Connections to the Report Server Database" in How
to: Configure a Report Server for Remote Administration.
If the error includes the following additional text, the password expired on the account used to run the Database Engine instance: "An error has occurred while establishing a connection
to the server. When connecting to SQL Server, this failure may be caused by the fact that under the default settings SQL Server does not permit remote connections. (provider: SQL Server Network Interfaces, error: 26 - Error Locating Server/Instance Specified)." To
resolve this error, reset the password.