The question of how to troubleshoot the 0-10v dimming comes up regularly, so here are the easy steps to determine if it is a wiring issue or driver issue.
1) At the first fixture take the grey and violet wires off the dimming circuit.
2) With the power on touch the grey and violet wires coming from the driver side together. This is causing a short and will cause the fixture to dim to minimal (which could look like off)
If the fixture dims when doing step 1 & 2 you most likely have a bad tap or a wire crossed in the line somewhere, so its best to start at the dimming control and work through the line until you find the point where the issue is located.
If the fixture does not respond when doing this you most likely have a driver issue and will need to contact your Post Sales rep to have them send a replacement driver.