Out of memory

<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 5.19.1

Error message:
Out of memory

Stack trace:
(00FBC671)
(00FBDC4B)
(000B0807)
(000C2BBB)
(00022350)
(000B1E59)
(00DBF3D8)
(00244192)
(003C79CC)
(0003FFC9) USER32.dll
(00036F95) USER32.dll
(00034CF5) USER32.dll
(00034ABB) USER32.dll.DispatchMessageW

Status: unknown_rel_addr

The problem happens rarely. I cannot reproduce it.