I had a BizTalk Web Service which is running for more than a year without any issues. Users are calling the Web Service from an Excel applicaiton to upload the list of items everyday, Suddenly yesterday when user tries to upload more than 20,000 line items we started getting an error “There was an exception running the extensions specified in the config file, ---> Maximum request length exceeded“.
First I thought there was no size limit in a SOAP message. Then I figured out you need to increase the request limit in the Web.Config or machine.Config on the server.
There is the maxRequestLength attribute in the httpRunTime element in the
machine.config file. By default its 4MB if you feel you might expect data more than 4MB then you can increase the size as accordingly Ex:- 8000KB
Web.Config of the Web Service
<configuration>
<system.web>
...
<httpRuntime maxRequestLength="8000"></httpRuntime> <!- Add this line ->
</system.web>
</configuration>
Or change the maxRequestLength attribute in the httpRuntime in machine.config from default 4096 to 8000