Error “Maximum request length exceeded” in Reporting Services
This error came up while trying to upload a 3.9Mb SSRS report to a new SQL 2008 R2 reporting server.
open the web.config file found in:
C:Program FilesMicrosoft SQL ServerMSRS10_50.#####Reporting ServicesReportServer
#### stands for your instance name
Modify line 40 or the line with below:
Restart just the reporting service. There is no need to restart the database service or reboot the server box.
You should now be able to upload reports up to 15000kb ie 15mb in this case. You can modify the value as needed.