The following section in the MSDL contains information on how to customize errors in Strategy Web:
Home > Web SDK > Customizing Strategy Web > Part I: Fundamentals of Customization > Scenarios: Altering Application Workflow and Navigation > Customizing Error Messages
Using the Strategy Web SDK 9.3.x, it is possible to customize error messages sent to Strategy Web by the Intelligence Server.
For this technical note we will take the following error message as an example:

(Maximum number of result rows retrieved per report was exceeded.Error in Process method of Component: AnalyticalEngineServer, Project Strategy Tutorial, Job 253, Error Code= -2147205488.) (com.Strategy.webapi.MSTRWebAPIException)
[com.Strategy.webapi SEVERE] [02/17/2010 11:41:39:277] [0] [Administrator] [192.168.1.33] [CDSSXMLReportServer.GetExecutionResultsEx] (Maximum number of result rows retrieved per report was exceeded.[3]Error in Process method of Component: AnalyticalEngineServer, Project Strategy Tutorial, Job 253, Error Code= -2147205488.) (com.Strategy.webapi.MSTRWebAPIException) 0x80043e90: [com.Strategy.webapi.MSTRWebAPIException: (Maximum number of result rows retrieved per report was exceeded.[3]Error in Process method of Component: AnalyticalEngineServer, Project Strategy Tutorial, Job 253, Error Code= -2147205488.)

CUSTOMIZATION WARNING:
This customization is provided as a convenience to Strategy users and is only directly applicable to the version stated. While this code may apply to other releases directly, Strategy Technical Support makes no guarantees that the code provided will apply to any future or previous builds. In the event of a code change in future builds, Strategy Technical Support makes no guarantee that an updated version of this particular customization will be provided. In the event of a code change in future builds, Strategy may not be able to provide additional code on this matter even though this customization is provided at this time for this specific build. For enhancements to this customization or to incorporate similar functionality into other versions, contact your Account Executive to inquire about Strategy Consulting assistance.