<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 6.0.2

Error message:
Ошибка доступа к памяти.

Трассировка стека:
(000C08DD) TTerminalManager::GetSessionTitle
(010048D6) C6085_0
(0100693E) ____ExceptionHandler
(010036F8) __ExceptionHandler
(00087ACF) ntdll.dll
(00073FA1) ntdll.dll.KiUserExceptionDispatcher
(00024B2C) TCustomScpExplorerForm::PopupTrayBalloon
(00024D60) TCustomScpExplorerForm::MoreMessageDialog
(000BECBF) TTerminalManager::TerminalQueryUser
(00DFB1ED) TTerminal::QueryUser
(00D696E6) TSecureShell::TimeoutPrompt
(00D6BAF6) TSecureShell::WaitForData
(00D68E8A) TSecureShell::Receive
(00D69108) TSecureShell::ReceiveLine
(00D46E82) TSCPFileSystem::ReadCommandOutput
(00D475B8) TSCPFileSystem::ExecCommand
(00D4777B) TSCPFileSystem::ExecCommand
(00D4BF79) TSCPFileSystem::AnyCommand
(00E0A3DC) TTerminal::DoAnyCommand
(00E05336) TTerminal::CustomCommandOnFiles
(0000C3CA) TCustomScpExplorerForm::RemoteCustomCommand
(0001072E) TCustomScpExplorerForm::CustomCommand
(0001204C) TCustomScpExplorerForm::ExecuteFileOperation
(000121F4) TCustomScpExplorerForm::ExecuteFileOperation
(000123B3) TCustomScpExplorerForm::ExecuteFileOperationCommand
(000541A8) TNonVisualDataModule::CustomCommandClick
(00214C20) System::Classes::_18201
(00040379) USER32.dll
(00037345) USER32.dll
(000350B5) USER32.dll
(00034E7B) USER32.dll.DispatchMessageW

(01004F41) C6085_0
(0100651B) _ReThrowException
(00DFB39B) TTerminal::QueryUser
(00D696E6) TSecureShell::TimeoutPrompt
(00D6BAF6) TSecureShell::WaitForData
(00D68E8A) TSecureShell::Receive
(00D69108) TSecureShell::ReceiveLine
(00D46E82) TSCPFileSystem::ReadCommandOutput
(00D475B8) TSCPFileSystem::ExecCommand
(00D4777B) TSCPFileSystem::ExecCommand
(00D4BF79) TSCPFileSystem::AnyCommand
(00E0A3DC) TTerminal::DoAnyCommand
(00E05336) TTerminal::CustomCommandOnFiles
(0000C3CA) TCustomScpExplorerForm::RemoteCustomCommand
(0001072E) TCustomScpExplorerForm::CustomCommand
(0001204C) TCustomScpExplorerForm::ExecuteFileOperation
(000121F4) TCustomScpExplorerForm::ExecuteFileOperation
(000123B3) TCustomScpExplorerForm::ExecuteFileOperationCommand
(000541A8) TNonVisualDataModule::CustomCommandClick
(00214C20) System::Classes::_18201
(00040379) USER32.dll
(00037345) USER32.dll
(000350B5) USER32.dll
(00034E7B) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.