Thanks for your report.
I have sent you an email with a debug version of WinSCP to address you have used to register on this forum.
<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 5.7.1
Error message:
Invalid access to memory.
Stack trace:
[0167DF88]
[01881962]
[018839CA]
[01880944]
[77BC023E] ntdll.dll.ZwWow64CallFunction64
[77BC09BA] ntdll.dll.KiUserExceptionDispatcher
[017C7E7C]
[017C7753]
[017C75C7]
[017C7296]
[017AA8F2]
[017135B7]
[0170E598]
[011231F7]
[77837C02] KERNEL32.DLL.BaseThreadInitThunk
[77BDB54D] ntdll.dll
[77BDB515] ntdll.dll
Connection failed.