The thing that doesn't make sense is how they all fail at same time unless it is improper voltage/connected to wrong voltage tap or a lightning event. Lightning probably would see other items effected as well, unless these lights is about all there is to have any damages.
Wrong voltage tap will show up fast if you mess up with 120 vs other taps, but using the wrong 208, 240 or 277 taps could result in the thing working but will take some time to burn out. Supply the unit with nominal 208 but is running near 215 - and it may run a very long time if connected to the 240 tap, supply it with nominal 240 but is running near 250 - it may run a long time if connected to the 277 tap - many of these units are set up for 277 as shipped - maybe the installer didn't pay close enough attention to what tap was used?