Invalid access to memory - System::Syncobjs::TCriticalSection::Acquire

<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 6.1.1

Error message:
Invalid access to memory.

Stack trace:
(00063EF5) ntdll.dll
(0100350E) C6083_0
(01005576) ____ExceptionHandler
(01002330) __ExceptionHandler
(000974CF) ntdll.dll
(00077751) ntdll.dll.KiUserExceptionDispatcher
(00042F93) ntdll.dll
(00042D54) ntdll.dll.RtlEnterCriticalSection
(0025DDC7) System::Syncobjs::TCriticalSection::Acquire
(00D1B8F6) TTerminalQueue::CreateStatus
(0000816D) TCustomScpExplorerForm::UpdateQueueStatus
(00008634) TCustomScpExplorerForm::QueueChanged
(0000809E) TCustomScpExplorerForm::SetQueue
(000BDF38) TTerminalManager::UpdateScpExplorer
(000C07FC) TTerminalManager::SessionReady
(000BDE7C) TTerminalManager::FreeTerminal
(000BD1EF) TTerminalManager::FreeActiveTerminal
(00C90612) TThemePageControl::Dispatch
(003F62DD) Vcl::Controls::TWinControl::WndProc
(003F5924) Vcl::Controls::TWinControl::MainWndProc
(00214D98) System::Classes::_18201
(000312E1) USER32.dll
(00022001) USER32.dll
(00021972) USER32.dll.CallWindowProcW
(004AFCAF) Dragdrop::TDragDrop::WndMethod
(00214D98) System::Classes::_18201
(000312E1) USER32.dll
(00022001) USER32.dll
(000208C0) USER32.dll
(0002040B) USER32.dll.DispatchMessageW

(01003B79) C6083_0
(01005153) _ReThrowException
(00D1B9C2) TTerminalQueue::CreateStatus
(0000816D) TCustomScpExplorerForm::UpdateQueueStatus
(00008634) TCustomScpExplorerForm::QueueChanged
(0000809E) TCustomScpExplorerForm::SetQueue
(000BDF38) TTerminalManager::UpdateScpExplorer
(000C07FC) TTerminalManager::SessionReady
(000BDE7C) TTerminalManager::FreeTerminal
(000BD1EF) TTerminalManager::FreeActiveTerminal
(00C90612) TThemePageControl::Dispatch
(003F62DD) Vcl::Controls::TWinControl::WndProc
(003F5924) Vcl::Controls::TWinControl::MainWndProc
(00214D98) System::Classes::_18201
(000312E1) USER32.dll
(00022001) USER32.dll
(00021972) USER32.dll.CallWindowProcW
(004AFCAF) Dragdrop::TDragDrop::WndMethod
(00214D98) System::Classes::_18201
(000312E1) USER32.dll
(00022001) USER32.dll
(000208C0) USER32.dll
(0002040B) 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 6.1.2

Error message:
Invalid access to memory.

Stack trace:
(0005E603) ntdll.dll
(01003DEA) C6083_0
(01005E52) ____ExceptionHandler
(01002C0C) __ExceptionHandler
(0008792F) ntdll.dll
(00073F81) ntdll.dll.KiUserExceptionDispatcher
(0003F125) ntdll.dll
(0003EF74) ntdll.dll.RtlEnterCriticalSection
(0025E67B) System::Syncobjs::TCriticalSection::Acquire
(00D1C1B6) TTerminalQueue::CreateStatus
(0000816D) TCustomScpExplorerForm::UpdateQueueStatus
(00008634) TCustomScpExplorerForm::QueueChanged
(0000809E) TCustomScpExplorerForm::SetQueue
(000BE7EC) TTerminalManager::UpdateScpExplorer
(000C10B0) TTerminalManager::SessionReady
(000BE730) TTerminalManager::FreeTerminal
(000BDAA3) TTerminalManager::FreeActiveTerminal
(00C90ED2) TThemePageControl::Dispatch
(003F6B91) Vcl::Controls::TWinControl::WndProc
(003F61D8) Vcl::Controls::TWinControl::MainWndProc
(0021564C) System::Classes::_18201
(0003FF49) USER32.dll
(00036EF5) USER32.dll
(000365D2) USER32.dll
(00034776) USER32.dll.CallWindowProcW
(004B0563) Dragdrop::TDragDrop::WndMethod
(0021564C) System::Classes::_18201
(0003FF49) USER32.dll
(00036EF5) USER32.dll
(00034C65) USER32.dll
(00034A2B) USER32.dll.DispatchMessageW

(01004455) C6083_0
(01005A2F) _ReThrowException
(00D1C282) TTerminalQueue::CreateStatus
(0000816D) TCustomScpExplorerForm::UpdateQueueStatus
(00008634) TCustomScpExplorerForm::QueueChanged
(0000809E) TCustomScpExplorerForm::SetQueue
(000BE7EC) TTerminalManager::UpdateScpExplorer
(000C10B0) TTerminalManager::SessionReady
(000BE730) TTerminalManager::FreeTerminal
(000BDAA3) TTerminalManager::FreeActiveTerminal
(00C90ED2) TThemePageControl::Dispatch
(003F6B91) Vcl::Controls::TWinControl::WndProc
(003F61D8) Vcl::Controls::TWinControl::MainWndProc
(0021564C) System::Classes::_18201
(0003FF49) USER32.dll
(00036EF5) USER32.dll
(000365D2) USER32.dll
(00034776) USER32.dll.CallWindowProcW
(004B0563) Dragdrop::TDragDrop::WndMethod
(0021564C) System::Classes::_18201
(0003FF49) USER32.dll
(00036EF5) USER32.dll
(00034C65) USER32.dll
(00034A2B) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.

a failed tentative was present, and this error can when opening a new session

WinSCP 6.1.2

Error message:
Accès mémoire invalide.

Trace de la pile :
(000643A5) ntdll.dll
(01003DEA) C6083_0
(01005E52) ____ExceptionHandler
(01002C0C) __ExceptionHandler
(000981DF) ntdll.dll
(00077D51) ntdll.dll.KiUserExceptionDispatcher
(00043443) ntdll.dll
(00043204) ntdll.dll.RtlEnterCriticalSection
(0025E67B) System::Syncobjs::TCriticalSection::Acquire
(00D1CE07) TTerminalQueue::GetIsEmpty
(0000A0C7) TCustomScpExplorerForm::AddQueueItem
(00017855) TCustomScpExplorerForm::ExecutedFileChanged
(00080B56) TEditorManager::CheckFileChange

(01004455) C6083_0
(01005A2F) _ReThrowException
(00080DB8) TEditorManager::CheckFileChange

The problem happens rarely. I cannot reproduce it.