Cannot focus a disabled or invisible window

<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:
Cannot focus a disabled or invisible window

Stack trace:
[014EBDC9]
[013213E1]
[01321AD2]
[0132704D]
[01326F22]
[016EA040]
[0152C7E5]
[01570713]
[01650708]
[75B97919] USER32.DLL.CallNextHookEx
[75B97B75] USER32.DLL
[75B9C7B9] USER32.DLL.CallWindowProcW
[72C73D70] COMCTL32.DLL.DefSubclassProc
[72C73D52] COMCTL32.DLL.DefSubclassProc
[72C71012] COMCTL32.DLL
[72C73B21] COMCTL32.DLL
[75B97919] USER32.DLL.CallNextHookEx
[75B97B75] USER32.DLL
[75B9C7B9] USER32.DLL.CallWindowProcW
[0170F2DF]
[01650708]
[75B97919] USER32.DLL.CallNextHookEx
[75B97B75] USER32.DLL
[75B997EF] USER32.DLL
[75B99854] USER32.DLL.DispatchMessageW

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.