Invalid access to memory - Vcl::Forms::TGlassFrame::FrameExtended

Trying to escape previously reported error.
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.15.9

Error message:
Invalid access to memory.

Stack trace:
(0023ED53) Vcl::Forms::TGlassFrame::FrameExtended
(0008402F) ntdll.dll
(00071931) ntdll.dll.KiUserExceptionDispatcher
(002746D5) Vcl::Controls::TControl::WndProc
(00279219) Vcl::Controls::TWinControl::WndProc
(002336E0) Vcl::Forms::TCustomForm::WndProc

The problem happens rarely. I cannot reproduce it.