The maxAllowedContentLength setting is specific to file uploads. This setting allows the Application Server to override an IIS security feature that prohibits requests over 30 million bytes (about 28.6 MB). This request filtering feature is enabled by default.
Note:
This setting doesn't override the maxRequestLength setting. If you increase the maxAllowedContentLength, you may also need to increase the maxRequestLength to accommodate larger files. The maxAllowedContentLength should exceed the maxRequestLength.
For more information about this setting, refer to the Application Server module reference guide.