Invalid access to memory - TTerminal::PeekCurrentDirectory

<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 6.1.2

Error message:
Invalid access to memory.

Stack trace:
(00DFCFAF) TTerminal::PeekCurrentDirectory
(0008792F) ntdll.dll
(00073F81) ntdll.dll.KiUserExceptionDispatcher
(00022178) TCustomScpExplorerForm::UpdateSessionData
(000220E3) TCustomScpExplorerForm::UpdateSession
(00021AC7) TCustomScpExplorerForm::DoCollectWorkspace
(0002E248) TCustomScpExplorerForm::FormClose
(003B05C7) Vcl::Forms::TCustomForm::DoClose
(003F6B91) Vcl::Controls::TWinControl::WndProc
(003B10A0) Vcl::Forms::TCustomForm::WndProc

The problem happens rarely. I cannot reproduce it.

<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 6.1.2

Error message:
Ошибка доступа к памяти.

Трассировка стека:
(00DFCFAF) TTerminal::PeekCurrentDirectory
(00087A7F) ntdll.dll
(000740D1) ntdll.dll.KiUserExceptionDispatcher
(00022178) TCustomScpExplorerForm::UpdateSessionData
(000220E3) TCustomScpExplorerForm::UpdateSession
(00007E80) TCustomScpExplorerForm::SessionChanging
(000BE8EF) TTerminalManager::DoSetActiveSession
(000BE840) TTerminalManager::SetActiveSession
(0001BD8E) TCustomScpExplorerForm::NewSession
(0001BDD7) TCustomScpExplorerForm::NewTab
(0002408B) TCustomScpExplorerForm::SessionTabSwitched
(00024108) TCustomScpExplorerForm::SessionsPageControlChange
(00423409) Vcl::Comctrls::TCustomTabControl::Change
(003F6B91) Vcl::Controls::TWinControl::WndProc
(003F1C88) Vcl::Controls::TControl::Perform
(003F6CF7) Vcl::Controls::_17076
(003F6B91) Vcl::Controls::TWinControl::WndProc
(003B10A0) Vcl::Forms::TCustomForm::WndProc

The problem happens rarely. I cannot reproduce it.