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 5.7.4

Error message:
Invalid access to memory.

Stack trace:
(003ADB4F) System::SysFreeMem
(0003EBFA) ntdll.dll
(0001D4AA) ntdll.dll.KiUserExceptionDispatcher
(007D133F) _free
(007BD029) operator delete
(006D4B5A) TSFTPFileSystem::ResetConnection
(006D35CF) TSFTPFileSystem::~TSFTPFileSystem
(0070A03F) TTerminal::~TTerminal
(0007531E) TManagedTerminal::~TManagedTerminal
(00076664) TTerminalManager::FreeTerminal
(00075CC7) TTerminalManager::FreeActiveTerminal
(00382054) System::Actions::TContainedActionList::ExecuteAction
(00169BB5) Vcl::Actnlist::TCustomAction::Execute