<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 5.21.6

Error message:
Invalid access to memory.

Stack trace:
(00E9A977) C3049_0
(000974CF) ntdll.dll
(00077751) ntdll.dll.KiUserExceptionDispatcher
(00E46240) __tpdsc__ std::unique_ptr<Vcl::Controls::TSizeConstraints, std::default_delete<Vcl::Controls::TSizeConstraints> >
(000566AF) TOwnConsole::TOwnConsole
(00018463) TCustomScpExplorerForm::KeyDown
(0040D614) System::Uiconsts::_16405
(001CF701) __tpdsc__ Vcl::Stdctrls::TGroupBox
(003C9C14) System::Win::Registry::TRegistry::ReadCurrency
(00031371) USER32.dll
(00022081) USER32.dll
(00020940) USER32.dll
(0002048B) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.