Invalid access to memory

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WinSCP 5.11.2

Error message:
Invalid access to memory.

Stack trace:
(00032E14)
(0008A52F) ntdll.dll
(00077DAA) ntdll.dll.KiUserExceptionDispatcher
(003BDE74)
(001A4F62)
(00216DCA)
(00216E48)

Status: unknown_rel_addr

The problem happens rarely. I cannot reproduce it.