<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.19.5

Error message:
メモリのアクセス違反

スタック トレース:
(00DB79CE) TSFTPFileSystem::Sink
(00FC4482) C5294_3
(00FC64EA) ____ExceptionHandler
(00FC32A4) __ExceptionHandler
(0008788F) ntdll.dll
(00073EC1) ntdll.dll.KiUserExceptionDispatcher
(00DE367C) TTerminal::DoCopyToLocal
(00DB3AB2) TSFTPFileSystem::CopyToLocal
(00DDFF20) TTerminal::CopyToParallel
(00CF60E7) TParallelTransferQueueItem::DoExecute
(00CF4A7A) TQueueItem::Execute
(00CF3AAA) TTerminalItem::ProcessEvent
(00CF1DF0) TSignalThread::Execute
(000C183B) Userinterface::C20_0
(0001EA27) KERNEL32.DLL.BaseThreadInitThunk
(00066A7C) ntdll.dll.RtlGetAppContainerNamedObjectPath
(00066A49) ntdll.dll.RtlGetAppContainerNamedObjectPath

(00DB79CE) TSFTPFileSystem::Sink
(00FC4482) C5294_3
(00FC64EA) ____ExceptionHandler
(00FC32A4) __ExceptionHandler
(0008788F) ntdll.dll
(00073EC1) ntdll.dll.KiUserExceptionDispatcher
(00DE367C) TTerminal::DoCopyToLocal
(00DB3AB2) TSFTPFileSystem::CopyToLocal
(00DDFF20) TTerminal::CopyToParallel
(00CF60E7) TParallelTransferQueueItem::DoExecute
(00CF4A7A) TQueueItem::Execute
(00CF3AAA) TTerminalItem::ProcessEvent
(00CF1DF0) TSignalThread::Execute
(000C183B) Userinterface::C20_0
(0001EA27) KERNEL32.DLL.BaseThreadInitThunk
(00066A7C) ntdll.dll.RtlGetAppContainerNamedObjectPath
(00066A49) ntdll.dll.RtlGetAppContainerNamedObjectPath

The problem happens rarely. I cannot reproduce it.