Internal Error server after cancellation of download by user on iis 8.5

In download at high speed (12 Mbps), after several times the cancellation of the download is made by the user of the server and the message is sent to the server’s international server. PHP version 7.0.1. Windows Server 2012 and iis8.5. please help.

There was no error in the PHP log


@c12simple can you have a look at this?