Thank you for posting!
The TBT3-UDV dock has one built-in DisplayPort video output. If this output needs to be converted to any other video standard, then an ‘Active’ video adapter is required, and we do our best to call this out in our product listings. It is for this reason that we include in the box with the dock an Active DisplayPort to HDMI adapter.
** ‘Passive’ video cables or adapters will not work ** Given your description of the behavior, the cable you have is a passive cable and that is why it is not working.
If you need to connect a single DVI display to the dock, the most inexpensive method would be to purchase separately a HDMI to DVI video cable such as this example --> http://amazon.com/dp/B014I8UQJY This cable can be used in conjunction with the included Active DisplayPort to HDMI adapter to connect your DVI display to the TBT3-UDV.
To put that another way, things would be connected like this:
TBT3-UDV dock built-in DisplayPort video output --> Active DisplayPort to HDMI adapter (included in box with dock) --> HDMI to DVI video cable (a cable with a HDMI connector on one end and a DVI connector on the opposite end, not included) --> DVI input of the display
Please let us know if you have any additional questions, and thank you for giving us the chance to help!