How to increase SharePoint file size limit

When you migrate documents to SharePoint, you might encouter import errors with the following (or a similar) message in the migration-center's log files:

Could not upload File! - Error: Server Error on upload request! Status Code:400 [The request message is too big. The server does not allow messages larger than 52428800 bytes.]

This can happen if you try to import files with content larger than 50 MB into SharePoint because the default SharePoint / IIS installation limits the file upload size to 50 MB.

The following article shows which settings need to be changed to import larger files into SharePoint:

https://blogs.technet.microsoft.com/praveenh/2012/11/15/issues-uploading-large-files-to-sharepoint/

For SharePoint 2016, please see also the following article:

https://social.technet.microsoft.com/wiki/contents/articles/34132.sharepoint-2016-increase-file-size-limit.aspx