<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 6.3.4

Error message:
External exception EEFFACE

Stack trace:
(0014A4C2) KERNELBASE.dll.RaiseException
(00098F2F) ntdll.dll
(000781B1) ntdll.dll.KiUserExceptionDispatcher
(00556838) Jclhookexcept::_16408
(00E23602) C6612_0
(00E249F3) _ReThrowException
(0001AA1E) TCustomScpExplorerForm::CalculateSize
(00D09E41) TPropertiesDialog::CalculateSizeButtonClick
(00404A1F) Vcl::Controls::TControl::Click
(00408FE1) Vcl::Controls::TWinControl::WndProc
(003712EC) Vcl::Stdctrls::TButtonControl::WndProc
(00409147) Vcl::Controls::_17076
(00408FE1) Vcl::Controls::TWinControl::WndProc
(00408628) Vcl::Controls::TWinControl::MainWndProc
(00226F2C) System::Classes::_18201
(00032431) USER32.dll
(00023231) USER32.dll
(00022CB5) USER32.dll
(0002CC1D) USER32.dll
(0007816B) ntdll.dll.KiUserCallbackDispatcher
(00038BB3) USER32.dll
(00021D11) USER32.dll.SendMessageW
(00000578)bdhkm32.dll
(00016EED) bdhkm32.dll
(000124B4) bdhkm32.dll
(0007472A) COMCTL32.DLL
(00084EF2) COMCTL32.DLL
(00032431) USER32.dll
(00023231) USER32.dll
(00022BA2) USER32.dll.CallWindowProcW
(004090F2) Vcl::Controls::TWinControl::DefaultHandler
(00408FE1) Vcl::Controls::TWinControl::WndProc
(003712EC) Vcl::Stdctrls::TButtonControl::WndProc
(00226F2C) System::Classes::_18201
(00032431) USER32.dll
(00023231) USER32.dll
(00021AF0) USER32.dll
(0002163B) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.

<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 5.9.2

Error message:
External exception EEFFACE

Трассировка стека:
(000D96F2) KERNELBASE.dll.RaiseException
(0008148F) ntdll.dll
(0006F02A) ntdll.dll.KiUserExceptionDispatcher
(004B8B7C) Jclhookexcept::_16408
(0086409A) C5073_3
(0086548B) _ReThrowException
(00014F50) TCustomScpExplorerForm::CalculateSize
(007F77F0) TPropertiesDialog::CalculateSizeButtonClick
(0024A63B) Vcl::Controls::TControl::Click
(0024EC29) Vcl::Controls::TWinControl::WndProc
(001B6DA0) Vcl::Stdctrls::TButtonControl::WndProc
(0024ED8F) Vcl::Controls::_17076
(0024EC29) Vcl::Controls::TWinControl::WndProc
(0024E270) Vcl::Controls::TWinControl::MainWndProc
(00372BEC) System::Classes::_18201
(0002C2B1) USER32.dll
(0000D885) USER32.dll
(0000D4BB) USER32.dll
(00017B07) USER32.dll
(0006F004) ntdll.dll.KiUserCallbackDispatcher
(0000FBFB) USER32.dll.SendMessageW
(0004C369) COMCTL32.DLL
(0005C060) COMCTL32.DLL
(0002C2B1) USER32.dll
(0000D885) USER32.dll
(0000CF12) USER32.dll.CallWindowProcW
(0024ED3A) Vcl::Controls::TWinControl::DefaultHandler
(0024EC29) Vcl::Controls::TWinControl::WndProc
(001B6DA0) Vcl::Stdctrls::TButtonControl::WndProc
(00372BEC) System::Classes::_18201
(0002C2B1) USER32.dll
(0000D885) USER32.dll
(0000D1DF) USER32.dll
(0000CF9B) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.

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 5.7.3

Error message:
External exception EEFFACE

Stack trace:
(0000B41F) KERNELBASE.dll.RaiseException
(0005A466) ntdll.dll
(0000F12E) ntdll.dll.KiUserExceptionDispatcher
(00495FDC) Jclhookexcept::_16408
(007E24F6) C4799_3
(007E38E7) _ReThrowException
(0001315C) TCustomScpExplorerForm::CalculateSize
(00779A38) TPropertiesDialog::CalculateSizeButtonClick
(00217907) Vcl::Controls::TControl::Click
(0021BEF5) Vcl::Controls::TWinControl::WndProc
(00184960) Vcl::Stdctrls::TButtonControl::WndProc
(0021C05B) Vcl::Controls::_17076
(0021BEF5) Vcl::Controls::TWinControl::WndProc
(0021B53C) Vcl::Controls::TWinControl::MainWndProc
(0033FE18) System::Classes::_18201
(000152F7) USER32.dll
(00015D35) USER32.dll
(00015DE3) USER32.dll
(00015E41) USER32.dll
(0000F107) ntdll.dll.KiUserCallbackDispatcher
(000186C0) USER32.dll.SendMessageW
(000A35FB) COMCTL32.DLL
(000A365E) COMCTL32.DLL
(000A34E8) COMCTL32.DLL
(000152F7) USER32.dll
(00015D35) USER32.dll
(0001FD22) USER32.dll
(0001FD48) USER32.dll.CallWindowProcW
(0021C006) Vcl::Controls::TWinControl::DefaultHandler
(0021BEF5) Vcl::Controls::TWinControl::WndProc
(00184960) Vcl::Stdctrls::TButtonControl::WndProc
(0033FE18) System::Classes::_18201
(000152F7) USER32.dll
(00015D35) USER32.dll
(000167BF) USER32.dll
(00016885) USER32.dll.DispatchMessageW