If you get this error in cairs:
‘Maximum request length exceeded’
Add the following line to the web.config file in the CEDC. Increase the maxRequestLength value until you no longer get the exception.
The "Default" is 4MB. If you get this error, try bumping it up to 10MB.
This attribute has to be added to the web.config file and it must be placed after the <system.web> tag.
In this example, maxRequestLength is 1GB.
executionTimeout is set to 10 minutes (600 seconds)
<httpRuntime
maxRequestLength="1048576"
executionTimeout="600"
/>
Here's the reference link:
http://www.websupergoo.com/helpupload50/source/2-tech_notes/3-web.config.htm