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 5.7.5

Error message:
Ошибка доступа к памяти.

Трассировка стека:
(0067B2EF) TRemoteFile::Duplicate
(007E39EA) C4799_0
(007E5A52) ____ExceptionHandler
(007E29CC) __ExceptionHandler
(0005A5DA) ntdll.dll
(0000F12E) ntdll.dll.KiUserExceptionDispatcher
(00672D8B) TTransferQueueItem::TTransferQueueItem
(006734E7) TDownloadQueueItem::TDownloadQueueItem
(00007153) TCustomScpExplorerForm::AddQueueItem
(0000C575) TCustomScpExplorerForm::ExecuteFileOperation
(0000CFA8) TCustomScpExplorerForm::ExecuteFileOperation
(0000D02F) TCustomScpExplorerForm::ExecuteFileOperationCommand
(00032119) TNonVisualDataModule::ExplorerActionsExecute
(003822E4) System::Actions::TContainedActionList::ExecuteAction
(00169E45) Vcl::Actnlist::TCustomAction::Execute

(007E4055) C4799_0
(007E562F) _ReThrowException
(0067B488) TRemoteFile::Duplicate
(00672D8B) TTransferQueueItem::TTransferQueueItem
(006734E7) TDownloadQueueItem::TDownloadQueueItem
(00007153) TCustomScpExplorerForm::AddQueueItem
(0000C575) TCustomScpExplorerForm::ExecuteFileOperation
(0000CFA8) TCustomScpExplorerForm::ExecuteFileOperation
(0000D02F) TCustomScpExplorerForm::ExecuteFileOperationCommand
(00032119) TNonVisualDataModule::ExplorerActionsExecute
(003822E4) System::Actions::TContainedActionList::ExecuteAction
(00169E45) Vcl::Actnlist::TCustomAction::Execute

I know how to reproduce the problem or the problem happens frequently enough. I wish to be contacted by the WinSCP team to help resolving the problem.