<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 5.13.5

Error message:
Acceso a memoria no válido

Traza de la pila:
(008BE7C1) __DynamicCastVCLptr
(008BED3E) C5105_0
(008C0DA6) ____ExceptionHandler
(008BDB60) __ExceptionHandler
(0007DABF) ntdll.dll
(0006B6E1) ntdll.dll.KiUserExceptionDispatcher
(00015548) TCustomScpExplorerForm::RemoteTransferFiles
(0000F3A7) TCustomScpExplorerForm::ExecuteFileOperation
(0000F580) TCustomScpExplorerForm::ExecuteFileOperation
(0000F607) TCustomScpExplorerForm::ExecuteFileOperationCommand
(00039723) TNonVisualDataModule::ExplorerActionsExecute
(003C3024) System::Actions::TContainedActionList::ExecuteAction
(001A8E05) Vcl::Actnlist::TCustomAction::Execute
(00380EE0) System::Classes::_18201
(0003AF19) USER32.dll
(000373E5) USER32.dll
(00036C99) USER32.dll
(00036A7B) USER32.dll.DispatchMessageW

(008BF3A9) C5105_0
(008C0983) _ReThrowException
(0001561C) TCustomScpExplorerForm::RemoteTransferFiles
(0000F3A7) TCustomScpExplorerForm::ExecuteFileOperation
(0000F580) TCustomScpExplorerForm::ExecuteFileOperation
(0000F607) TCustomScpExplorerForm::ExecuteFileOperationCommand
(00039723) TNonVisualDataModule::ExplorerActionsExecute
(003C3024) System::Actions::TContainedActionList::ExecuteAction
(001A8E05) Vcl::Actnlist::TCustomAction::Execute
(00380EE0) System::Classes::_18201
(0003AF19) USER32.dll
(000373E5) USER32.dll
(00036C99) USER32.dll
(00036A7B) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.