By default a client can’t upload files in plesk file manager larger then ~30MB . Unfortunately we have to let them upload bigger files because they like to use the  archive “uncompress” feature from file manager.

The error received in plesk is:

HTTP Error 404.13 – Not Found

The request filtering module is configured to deny a request that exceeds the request content length.

All you have to do to solve this :

%windir%\system32\inetsrv\appcmd set config “PleskControlPanel/” -section:requestFiltering -requestLimits.maxAllowedContentLength:104857600

which will set a 100MB limit for file uploads in plesk file manager.