I have moved your question to a more appropriate section of the Forum.
As a confirmation, in your main computer (it looks like you are using Windows), does the AD2 show up as a USB Serial Converter in the Windows Device Manager when you connect it?
I personally haven't seen this error before, so what I would try to do is reload the data in the EEPROM since it appears that the AD2 is properly getting power from the host computer. You can do this by pressing Alt+F11 on the Device Manger screen of the WaveForms software and then clicking on the "My device is not listed" button that appears at the top to find your device and re-program it. As Attila recommends latter on in this thread, don't do this if your device is already correctly recognized.
If this does not resolve the problem though, I will need to pass you off to @attila who is much more familiar with the WaveForms software.