Thanks for your report.
I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.

<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 5.7.7

Error message:
Error changing directory to '..'.

Invalid access to memory.

Stack trace:
#007142F9# TTerminal::ReadDirectory
#007E08AA# C4799_0
#007E2912# ____ExceptionHandler
#007DF88C# __ExceptionHandler
#0008A61F# ntdll.dll
#00077E7A# ntdll.dll.KiUserExceptionDispatcher
#0071021A# TTerminal::ReactOnCommand
#00616007# TUnixDirView::ChangeDirectory
#006144B6# TUnixDirView::ExecuteParentDirectory
#003D9EB8# Customdirview::TCustomDirView::Execute
#0021C609# Vcl::Controls::TWinControl::WndProc
#00260537# Vcl::Comctrls::TCustomListView::WndProc
#0034059C# System::Classes::_18201
#000374F1# USER32.dll
#00015C3B# USER32.dll
#000159D2# USER32.dll.CallWindowProcW
#00098CBA# COMCTL32.DLL
#00098CA1# COMCTL32.DLL
#00098ADC# COMCTL32.DLL
#000374F1# USER32.dll
#00015C3B# USER32.dll
#000159D2# USER32.dll.CallWindowProcW
#003FF173# Dragdrop::TDragDrop::WndMethod
#0034059C# System::Classes::_18201
#000374F1# USER32.dll
#00015C3B# USER32.dll
#0001553C# USER32.dll
#000152FB# USER32.dll.DispatchMessageW

I know how to reproduce the problem or the problem happens frequently enough. I wish to be contacted by the WinSCP team to help resolving the problem.