Privileged instruction

<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:
Privileged instruction

Stack trace:
(0005F075)
(00087A5F) ntdll.dll
(00073F81) ntdll.dll.KiUserExceptionDispatcher
(00480368)
(00492ADE)
(0047FFF9)
(003CCDAF)
(00214D98)
(000400D9) USER32.dll
(000370A5) USER32.dll
(00034E15) USER32.dll
(00034BDB) USER32.dll.DispatchMessageW

Status: unknown_rel_addr

The problem happens rarely. I cannot reproduce it.