<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:
Invalid access to memory.

Stack trace:
(0029466B) System::DoneExcept
(0009783F) ntdll.dll
(000777B1) ntdll.dll.KiUserExceptionDispatcher
(00214D98) System::Classes::_18201
(000313B1) USER32.dll
(000221B1) USER32.dll
(00020A70) USER32.dll
(000205BB) USER32.dll.DispatchMessageW

(00294258) System::HandleAnyException
(0009783F) ntdll.dll
(000777B1) ntdll.dll.KiUserExceptionDispatcher
(00214D98) System::Classes::_18201
(000313B1) USER32.dll
(000221B1) USER32.dll
(00020A70) USER32.dll
(000205BB) USER32.dll.DispatchMessageW

Status: all_insignificant

The problem happens rarely. I cannot reproduce it.