5.7.0: Issue when copying big file (>200MB)

There is an error:
Hosting is not communicating for more than 15 sec
while copying big files (200MB)
turnning off 'Optimize connection buffer' does not help.
Can you please help me solve this issue ?
BTW in Winscp 4.2.9 the issue was not exist. ( I have this version )

Thanks for your report.

Can you send me an email, so I can send you back a debug version of WinSCP to track the problem? Please include link back to this topic in your email. Also note in this topic that you have sent the email. Thanks.