Thanks for your report.
I have sent you an email.

Copy >100GB by LAN between old XP PC (Server, xlite ftp 3.8.3.5, eval version) and new Win8 PC (Winscp 5.6.3, build 4824), occured after about 12 hours. Both eval Versions installed just before starting the transfer.

Client computer (Win8) was not used during the transfer/no other programms started by user. Mimimal CPU usage.
Server Computer (PC) ran firefox - High CPU usage but no network problems. Nothing crashed at the server.


WinSCP 5.6.3

Error message:
Division by zero

Stack trace:
[01455CA3]
[77C6C84E] ntdll.dll
[77C6C6B6] ntdll.dll.KiUserExceptionDispatcher
[0157C7CE]
[0157C75C]
[0102BA99]
[00F94504]
[0102BBFF]
[0102BA99]
[00FE683C]
[01590D29] @@Synchronizeprogress@Finalize
[0102B0E0]
[0114F9BC]
[77317919] USER32.DLL.CallNextHookEx
[77317B75] USER32.DLL
[77317CC8] USER32.DLL
[77317E21] USER32.DLL
[77C6C68F] ntdll.dll.KiUserCallbackDispatcher
[7731CB87] USER32.DLL.SendMessageW
[7519A2DC] COMCTL32.DLL
[75151935] COMCTL32.DLL
[77317919] USER32.DLL.CallNextHookEx
[77317B75] USER32.DLL
[7731C7B9] USER32.DLL.CallWindowProcW
[0102BBAA]
[0102BA99]
[00F94504]
[0114F9BC]
[77317919] USER32.DLL.CallNextHookEx
[77317B75] USER32.DLL
[77317CC8] USER32.DLL
[77317E21] USER32.DLL
[77C6C68F] ntdll.dll.KiUserCallbackDispatcher
[0102BA99]
[00FE683C]
[01590D29] @@Synchronizeprogress@Finalize
[0102B0E0]
[0114F9BC]
[77317919] USER32.DLL.CallNextHookEx
[77317B75] USER32.DLL
[77317CC8] USER32.DLL
[77317E21] USER32.DLL