<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 5.19.4

Error message:
Out of memory

スタック トレース:
(00439B3A)
(00439B3A)
(00E3F437)
(00E40BE3)
(00E43599)
(000F4953)
(000F51C4)
(000F533E)
(000F6E8C)
(000C2BC8)
(000C1FFC)
(00002658)
(00FC2011)
(00066A9C)ntdll.dll
(00066A69)ntdll.dll

Status: unknown_rel_addr

The problem happens rarely. I cannot reproduce it.