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 getting name of current remote directory.

Privileged instruction

Stack trace:
(002DF062) System::Generics::Defaults::TComparer__1<System::Generics::Collections::TPair__2<System::Typinfo::TTypeInfo *, System::UnicodeString> >::
(007E08AA) C4799_0
(007E2912) ____ExceptionHandler
(007DF88C) __ExceptionHandler
(0007C54F) ntdll.dll
(00069D8A) ntdll.dll.KiUserExceptionDispatcher
(00714252) TTerminal::ReadCurrentDirectory
(00710206) TTerminal::ReactOnCommand
(007113FA) TTerminal::SetCurrentDirectoryW
(0061594A) TUnixDirView::SetPath
(0002167E) TCustomScpExplorerForm::RemotePathComboBoxItemClick
(0043B305) Tbxextitems::TTBXComboBoxItem::DoListClick
(0034059C) System::Classes::_18201
(00033921) USER32.dll
(0001378B) USER32.dll
(0001308C) USER32.dll
(00012E4B) 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.