Invalid access to memory - RethrowException

<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 6.3.6

Error message:
Accès mémoire invalide.

Trace de la pile :
(00E253C1) C6612_3
(00E268F4) _ThrowExceptionLDTC
(00B2E437) RethrowException
(00B7ECA5) TTerminalThread::Rethrow
(00B7E85E) TTerminalThread::Idle
(000C5F53) TTerminalManager::Idle
(0001C62A) TCustomScpExplorerForm::Idle
(00055027) TNonVisualDataModule::DoIdle
(00054FE4) TNonVisualDataModule::SessionIdleTimerTimer
(00226F74) System::Classes::_18201
(00032431) USER32.dll
(00023231) USER32.dll
(00021AE0) USER32.dll
(0002162B) USER32.dll.DispatchMessageW

(00E253C1) C6612_3
(00E2699B) _ReThrowException
(000C5FB2) TTerminalManager::Idle
(0001C62A) TCustomScpExplorerForm::Idle
(00055027) TNonVisualDataModule::DoIdle
(00054FE4) TNonVisualDataModule::SessionIdleTimerTimer
(00226F74) System::Classes::_18201
(00032431) USER32.dll
(00023231) USER32.dll
(00021AE0) USER32.dll
(0002162B) 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 6.3.6

Error message:
Invalid access to memory.

Stack trace:
(00E253C1) C6612_3
(00E268F4) _ThrowExceptionLDTC
(00B2E437) RethrowException
(00B7ECA5) TTerminalThread::Rethrow
(00B7E85E) TTerminalThread::Idle
(000C5F53) TTerminalManager::Idle
(0001C62A) TCustomScpExplorerForm::Idle
(00055027) TNonVisualDataModule::DoIdle
(00054FE4) TNonVisualDataModule::SessionIdleTimerTimer
(00226F74) System::Classes::_18201
(000406A9) USER32.dll
(00036E15) USER32.dll
(0003574C) USER32.dll
(0003526B) USER32.dll.DispatchMessageW

(00E253C1) C6612_3
(00E2699B) _ReThrowException
(000C5FB2) TTerminalManager::Idle
(0001C62A) TCustomScpExplorerForm::Idle
(00055027) TNonVisualDataModule::DoIdle
(00054FE4) TNonVisualDataModule::SessionIdleTimerTimer
(00226F74) System::Classes::_18201
(000406A9) USER32.dll
(00036E15) USER32.dll
(0003574C) USER32.dll
(0003526B) 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.

@lady.perez: 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.