Performing standard SFTP backup routine, new and changed files only.

WinSCP 5.8.2

Error message:
Copying files to remote side failed.

Invalid access to memory.

Stack trace:
(003C87E8) System::SysFreeMem
(0084095E) C5073_3
(008429C6) ____ExceptionHandler
(0083F940) __ExceptionHandler
(0005A7EA) ntdll.dll
(0000F15E) ntdll.dll.KiUserExceptionDispatcher
(0082E88B) ___org_free
(0081A575) operator delete
(0081A548) operator delete[]
(0071F028) TSFTPFileSystem::ReceiveResponse
(0073DFD8) TSFTPFileSystem::SFTPSourceRobust
(00744A6D) TSFTPFileSystem::SFTPDirectorySource
(0073E418) TSFTPFileSystem::SFTPSource
(0073DFD8) TSFTPFileSystem::SFTPSourceRobust
(00744A6D) TSFTPFileSystem::SFTPDirectorySource
(0073E418) TSFTPFileSystem::SFTPSource
(0073DFD8) TSFTPFileSystem::SFTPSourceRobust
(00744A6D) TSFTPFileSystem::SFTPDirectorySource
(0073E418) TSFTPFileSystem::SFTPSource
(0073DFD8) TSFTPFileSystem::SFTPSourceRobust
(00744A6D) TSFTPFileSystem::SFTPDirectorySource
(0073E418) TSFTPFileSystem::SFTPSource
(0073DFD8) TSFTPFileSystem::SFTPSourceRobust
(00744A6D) TSFTPFileSystem::SFTPDirectorySource
(0073E418) TSFTPFileSystem::SFTPSource
(0073DFD8) TSFTPFileSystem::SFTPSourceRobust
(0073D166) TSFTPFileSystem::CopyToRemote
(00769231) TTerminal::CopyToRemote
(006AB6B3) TUploadQueueItem::DoExecute
(006A8E8E) TTerminalItem::ProcessEvent
(006A7334) TSignalThread::Execute
(00094477) Userinterface::C20_0
(00012388) kernel32.dll.BaseThreadInitThunk
(00038A00) ntdll.dll
(000389D0) ntdll.dll

(00840FC9) C5073_3
(008425A3) _ReThrowException
(0

The problem happens rarely. I cannot reproduce it.