When you call a BW Web Application, the system displays the error message "HTTP Error 403 - Forbidden" or "You are not authorized to view this page" (if the "Show friendly HTTP error messages" parameter has been deactivated, the system displays error message "service is not active").
Using Transaction SICF, check whether the service nodes under "sap/bw/*" were activated. You can use the context menu to activate these nodes.
When you activate the "sap/bw" node, ensure that you use the 'Yes' button with the icon (for all subnodes) (see also the info button for the activation dialog box), as in this way, you also activate all nodes below the service.
If you are using the BSP registration procedure, you must also activate the services mentioned in Note 517484.
In the SEM environment, ensure that the service for your Web interface has been activated under "sap/bc/bsp/sap/...".