rsInvalidReportServerDatabase
I had two different systems on which Microsoft SQL Server 2005 Reporting
Services are installed and configured. I decided to use one of the servers as a
web server and use the other one as the database server. I tried to reconfigure
one by using the Reporting Services Configuration tool. Although the
configuration for pointing a new reportserver database and a temp database
installed on another server was successful, browsing the Reports home page
resulted in with the following error:

Error
The version of the report server database is either in a format that is not
valid, or it cannot be read.
The found version is 'C.0.8.43'. The expected version is 'C.0.8.40'. To continue,
update the version of the
report server database and verify access rights. (rsInvalidReportServerDatabase)
I later realized that on one of the servers, MS SQL Server 2005 Service Pack
1 (SP1) is installed. But on the other server SP1 for SQL Server 2005 is not
installed.
Before reconfiguring the current installations, I upgraded the existing
installation by running the Service Pack 1 for the Microsoft SQL Server 2005.