How to fix the "Maximum request length exceeded" error in SSRS?

When exporting large reports or processing heavy datasets in SQL Server Reporting Services (SSRS), users often encounter the following error:

System.Web.Services.Protocols.SoapException: Maximum request length exceeded.

Why does this error occur?

This issue happens because ASP.NET enforces a default limit on the maximum HTTP request size (usually 4096 KB / 4 MB) to prevent denial-of-service attacks. When a report payload exceeds this limit, the request is blocked.

How to resolve it:

To fix this, you need to modify the web.config file on your SSRS Report Server.

<configuration>
  <system.web>
    <httpRuntime maxRequestLength="2097151" executionTimeout="9000" />
  </system.web>
</configuration>

Update maxRequestLength to a higher value in KB (e.g., 2097151 for 2 GB) and restart the SSRS service.