A log-file is created but nothing is written to it.
Sometimes vvvv becomes kind of unresponsive (because the TTY renderer gets the focus) until the Log Messages of TTY is set to false or its window is closed by ctrl+w (selecting the node and deleting it doesn’t work).
TTY says:
00:04:58 ERR : can not write to log file D:\VLC-Debug\Patches\logs\Test_2013.05.28-08.38.32.log
LogFileBug.v4p (3.9 kB)