Some background:
When one clicks in Setup/FTP to send an FTP Test Message, the camera stores the test message in the server at "Host Name"+"Path".
(incidentally, explicitly placing a "/" at the beginning of Path *appears* to be optional under v1.09).
However, before writing the TestMessage image to the server, the camera generates a Date/Time Suffix folder (at least, when that option is selected) named as the appropriate time interval inside the appropriate Day folder. If there are no motion triggers during that interval, then this folder remains empty. This can lead to confusion.
Recommendation: Test Message should go into the new created folder; or, do not create new folder, in response to TestMessage request.
This behavior was discovered while reviewing server logs, during troubleshooting of the inability of DCS-930L cameras to write to named domain as Host Name (workaround: numeric IP).