<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 6.1.1

Error message:
Unzulässiger Zugriff auf einen Speicherbereich.

Stapelverfolgung:
(00E51E38) TFileFindDialog::StartStopButtonClick
(0006246E) ntdll.dll
(0000F12E) ntdll.dll.KiUserExceptionDispatcher
(003F1799) Vcl::Controls::TControl::WndProc
(003F62DD) Vcl::Controls::TWinControl::WndProc

The problem happens rarely. I cannot reproduce it.