On adding a new document link to the document library a 404 error is encountered

Possible Cause

A possible cause of the error is that the file is too large for the system to link.  By default IIS limits links to a file size of 30MB.


The default limit needs to be increased. To override the default, a key needs to be added (or altered if it already exists) into the Mainpac web.config. Refer to the example below where the limit has been increased to 50MB. This is added directly below the <System.webserver> section of the web.config 

        <requestLimits maxAllowedContentLength="50000000" />


Alternate causes of the 404 error to investigate include:

  • security access to the file
  • invalid file type
  • invalid file name