By default, Essentials will refuse to handle any request that exceeds 20MB in size. This can be a conservative value for clients who regularly deal with large volumes of data.
To increase this limit, modify two settings in the web.config. file: the maximum allowed content length for security filtering, and the maximum request length for the HTTP Runtime.
The <requestLimits> tag within <system.webServer> sets the maximum allowed content length. This value is in bytes.:
<security> <requestFiltering> <requestLimits maxAllowedContentLength="20971520" /> </requestFiltering> </security>
The <httpRuntime> tag found within the <system.web> tag sets the maximum request length. This value is in kilobytes:
<httpRuntime maxRequestLength="20480" requestValidationMode="2.0" enableVersionHeader="false" />
The maximum you may use here is 4194303. That's 4 gigabytes. We recommend something closer to the default of 20480 (20Mb).
A maximum setting of 20Mb does not necessarily mean a 20Mb file will be permitted, this is due to file encoding which can take up as much as 33%. You will need to adjust the setting accordingly.