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 5.15.1

Error message:
获取当前远程目录名出错。

无效的内存访问。

Stack trace:
(0023F043) Vcl::Forms::TScrollingStyleHook::DrawVertScroll
(0092636E) C5153_3
(009283D6) ____ExceptionHandler
(00925190) __ExceptionHandler
(00089BEF) ntdll.dll
(00070AB1) ntdll.dll.KiUserExceptionDispatcher
(0081AE16) TTerminal::ReadCurrentDirectory
(0081641F) TTerminal::ReactOnCommand
(006CF3BD) TUnixDirView::ChangeDirectory
(006CD812) TUnixDirView::ExecuteParentDirectory
(0044598B) Customdirview::TCustomDirView::Execute
(0044330A) Customdirview::TCustomDirView::DoExecute
(00443F09) Customdirview::TCustomDirView::WMLButtonDblClk
(00278809) Vcl::Controls::TWinControl::WndProc
(002BBAE3) Vcl::Comctrls::TCustomListView::WndProc
(003A346C) System::Classes::_18201
(0001D0B9) USER32.dll
(00027844) USER32.dll
(0002A140) USER32.dll
(00027335) USER32.dll
(0000EBA6) USER32.dll.CallWindowProcW
(0004E318) COMCTL32.DLL
(0004E3B5) COMCTL32.DLL
(0004E15C) COMCTL32.DLL
(0001D0B9) USER32.dll
(00027844) USER32.dll
(0002A140) USER32.dll
(00027335) USER32.dll
(0000EBA6) USER32.dll.CallWindowProcW
(0047A29F) Dragdrop::TDragDrop::WndMethod
(003A346C) System::Classes::_18201
(0001D0B9) USER32.dll
(00027844) USER32.dll
(0002A140) USER32.dll
(000180D7) USER32.dll
(00017C1B) USER32.dll.DispatchMessageW

(009269D9) C5153_3
(00927FB3) _ReThrowException
(00817

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.