@bonny3: Thanks for your report.
I have sent you an email with a debug version of WinSCP to the 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 5.21.7

Error message:
Errore richiesta elenco cartelle '/home/frocchialando/public_html/image/cache/data/luxottica_14'.

Out of memory

Stack trace:
(00440118) System::DynArraySetLength
(00440118) System::DynArraySetLength
(00440249) System::DynArraySetLength
(003B0B9F) System::Classes::TStringList::AddObject
(003AF052) System::Classes::TStrings::Assign
(003B0BE2) System::Classes::TStringList::Assign
(00DE1F68) TTerminal::CustomReadDirectory
(00DE12D1) TTerminal::ReadDirectory
(00DE06C0) TTerminal::ReloadDirectory
(00C79A63) TUnixDirView::ReloadDirectory
(0002E140) TCustomScpExplorerForm::ReloadDirectory
(00048EAF) TNonVisualDataModule::ExplorerActionsExecute
(0040D640) System::Actions::TContainedActionList::ExecuteAction
(001CF72D) Vcl::Actnlist::TCustomAction::Execute
(003C9C40) System::Classes::_18201
(000400E9) USER32.dll
(000370A5) USER32.dll
(00034E15) USER32.dll
(00034BDB) USER32.dll.DispatchMessageW

(00FDFE2D) C5412_0
(00FE1407) _ReThrowException
(00D2E2F6) TSCPFileSystem::ReadDirectory
(00DE1F68) TTerminal::CustomReadDirectory
(00DE12D1) TTerminal::ReadDirectory
(00DE06C0) TTerminal::ReloadDirectory
(00C79A63) TUnixDirView::ReloadDirectory
(0002E140) TCustomScpExplorerForm::ReloadDirectory
(00048EAF) TNonVisualDataModule::ExplorerActionsExecute
(0040D640) System::Actions::TContainedActionList::ExecuteAction
(001CF72D) Vcl::Actnlist::TCustomAction::Execute
(003C9C40) System::Classes::_18201
(000400E9) USER32.dll
(000370A5) USER32.dll
(00034E15) USER32.dll
(00034BDB) USER32.dll.DispatchMessageW

(00FDFE2D) C5412_0
(00FE1407) _ReThrowException
(00DE1F97) TTerminal::CustomReadDirectory
(00DE12D1) TTerminal::ReadDirectory
(00DE06C0) TTerminal::ReloadDirectory
(00C79A63) TUnixDirView::ReloadDirectory
(0002E140) TCustomScpExplorerForm::ReloadDirectory
(00048EAF) TNonVisualDataModule::ExplorerActionsExecute
(0040D640) System::Actions::TContainedActionList::ExecuteAction
(001CF72D) Vcl::Actnlist::TCustomAction::Execute
(003C9C40) System::Classes::_18201
(000400E9) USER32.dll
(000370A5) USER32.dll
(00034E15) USER32.dll
(00034BDB) USER32.dll.DispatchMessageW

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.