>I was trying to increase the maximum file size supported in upload. When I change those values from web.config:
>
>system.web\httpRuntime\maxRequestLength="40000" to 50000
>system.webServer\validation\security\requestFiltering\requestLimits maxAllowedContentLength="4000000000" to 5000000000
>
>I got:
>
>500 - Internal server error.
>There is a problem with the resource you are looking for, and it cannot be displayed.
>
>Is there a maximum value that IIS\ASP.NET would be bound to?
>
>I didn't have any problem increasing from 10, 20, and 40 MB.


From here:
https://www.dnnsoftware.com/wiki/working-with-large-files

Maximum File sizes

Maximum file sizes differ based on the operating system and its associated version of Internet Information Server (IIS). In most cases, sites will be hosted on IIS7
or later ( as IIS6 is no longer supported by Microsoft), so the maximum size of a file is the smallest of the two settings. The maxRequestLength indicates the maximum
file upload size supported by ASP.NET, the maxAllowedContentLength specifies the maximum length of content in a request supported by IIS. Hence, we need to set
both maxRequestLength and maxAllowedContentLength values to upload large files.

One thing to be aware of is that although maxRequestLength is stored as a .net integer and therefore can be set as high as 2147483647 (approximately 2000 GB),
maxAllowedContentLength is stored as a .net uint and therefore can only store numbers as high as 4,294,967,295 (approximately 4GB as the value is for size in bytes).
This means that the maximum size for a file for any recent version of IIS is 4GB.