An error has occurred: Could not initialize Report Engine server. (Error: RWI 00226)

Well this is a common error that can occur during using the so called Business Objects XI R2 when we try to create a Web Intelligence Report.
The reason of this error is that the Web Intelligence Report Server is not running.
To run the server go to the Cenral Configuration Management and Start it the the Web Intelligence Report Server.
If its already running then go to the Central Management Console through the Administration Launchpad and click on Servers and start the Web Intelligence Report Server.
If you tried to run the server and it doesn't want to start then open the Registry ( type regedit in the Run ) and go to the following path "HKEY_LOCAL_MACHINE\Software\Business Objects\Suite 11.5\Enterprise\InstallRoot" and change the string value "Path" to directory of Business Objects 11.5 .
And then try to start the Web Intelligence Report Server again.

I know you will wonder why the value is changed, possible reason is the installion of a new Business Objects software like Xcelsius set the directory to Business Objects 12.0 instead of 11.5