<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 6.1.1

Error message:
无效的内存访问。

Stack trace:
(01003B79) C6083_0
(01005153) _ReThrowException
(00E17AAA) TTerminal::SinkRobust
(00E19253) TTerminal::SinkFile
(00E01842) TTerminal::ProcessDirectory
(00E1840A) TTerminal::Sink
(00E17A18) TTerminal::SinkRobust
(00E17840) TTerminal::DoCopyToLocal
(00DE79A2) TSFTPFileSystem::CopyToLocal
(00E17334) TTerminal::CopyToLocal
(00011511) TCustomScpExplorerForm::ExecuteCopyMoveFileOperation
(00012004) TCustomScpExplorerForm::ExecuteFileOperation
(0001224C) TCustomScpExplorerForm::ExecuteFileOperation
(00025BCB) TCustomScpExplorerForm::RemoteFileControlFileOperation
(00026001) TCustomScpExplorerForm::RemoteFileControlDDEnd
(0047BFBA) Customdirview::TCustomDirView::DDDragDetect
(00C92C52) TUnixDirView::DDDragDetect
(0047817A) Customdirview::TCustomDirView::CNNotify
(003F1799) Vcl::Controls::TControl::WndProc
(003F62DD) Vcl::Controls::TWinControl::WndProc
(004395B7) Vcl::Comctrls::TCustomListView::WndProc
(003F6443) Vcl::Controls::_17076
(003F62DD) Vcl::Controls::TWinControl::WndProc
(003F5924) Vcl::Controls::TWinControl::MainWndProc
(00214D98) System::Classes::_18201
(00040999) USER32.dll
(00036DB5) USER32.dll
(000369B5) USER32.dll
(0003AEBD) USER32.dll
(000740DB) ntdll.dll.KiUserCallbackDispatcher
(000350B8) USER32.dll.SendMessageW
(00068881) COMCTL32.DLL
(0019EEF0) COMCTL32.DLL
(000A4C84) COMCTL32.DLL
(000648A2) COMCTL32.DLL
(00040999) USER32.dll
(00036DB5) USER32.dll
(00036571) USER32.dll.GetSystemMetricsForDpi
(00034D96) USER32.dll.CallWindowProcW
(003F63EE) Vcl::Controls::TWinControl::DefaultHandler
(00479BCE) Customdirview::TCustomDirView::WMLButtonDown
(003F62DD) Vcl::Controls::TWinControl::WndProc
(004395B7) Vcl::Comctrls::TCustomListView::WndProc
(00214D98) System::Classes::_18201
(00040999) USER32.dll
(00036DB5) USER32.dll
(00036571) USER32.dll.GetSystemMetricsForDpi
(00034D96) USER32.dll.CallWindowProcW
(00079E97) COMCTL32.DLL
(00079F36) COMCTL32.DLL
(00079CEC) COMCTL32.DLL
(00040999) USER32.dll
(00036DB5) USER32.dll
(00036571) USER32.dll.GetSystemMetricsForDpi
(00034D96) USER32.dll.CallWindowProcW
(004AFCAF) Dragdrop::TDragDrop::WndMethod
(00214D98) System::Classes::_18201
(00040999) USER32.dll
(00036DB5) USER32.dll
(000356EC) USER32.dll
(0003520B) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.