The report server cannot open a connection to the report server database.

I ran into something interesting today with our VM template. 

When I change the machine name, I can run the SQL script on the desktop to correct the SQL server. After reboot, all seems fine. ReportServer services even start up with no error.

However, if I try to run an SSRS report, or even connect to http://localhost/reports, I get an error:

"The report server cannot open a connection to the report server database."

This is because the report server configuration records the SQL server that the ReportServer database resides on (and even the name of the ReportServer database, in case you want to really confuse people by changing it). 

If this happens to you, this is how you fix it:

1. Launch Reporting Services Configuration Manager
2. Click database from the menu at the left.
3. On the right, you will see you old SQL Server name.  Click change database.
4. Select Choose an existing report server database, then next
5. Enter your new SQL Server name and test connection, then click next
6. For Report Server Database, select ReportServer, then Next x3
7. Then finish

If you have WennSoft reports setup, you can run this to correct those paths:
WS_SetReplacementReportsForSRS