We released a fix right now, just run the FSDT Live Update to get it.
This will only work for FSDT and Simmarket customers. If you bought the scenery on the MS Marketplace, you'll have to wait for it to be approved for release, we don't know exactly how much time it will take ( I guess many other developers are sending their patches now ), but we sent the update to the MS Marketplace right now.
Now, before anyone asks "why FSDT is releasing a patch, when they keep saying it's a bug in the sim and it's MS/Asobo that should fix it ?", I'll explain exactly what's really happening here:
It's very well know that it's enough to just recompile the scenery with the latest simulator/SDK to fix the taxiway lights problem, we found this hours after the update came out and I've explained it on the SDK section of the official MSFS forum too, so that's hardly news.
However, not all sceneries can be patched this way, because of ANOTHER BUG in the scenery compiler: if a scenery contains more than one Projected Mesh ( custom ground textures/markings/etc. ) it's not possible to compile it with the new SDK, because the resulting scenery won't show up all the ground textures correctly. It's clearly a new bug, because the same scenery compiled with the old SDK works just fine, but with messed up taxiway lights. This bug happens only if the scenery has at least TWO Projected Mesh elements.
The messed up lights affects ALL our airport EXCEPT Quiberon ( because it's a day only airport with no lights ), but Key West contained only ONE Projected Mesh, so it's the only one we could recompile without losing any ground textures/markings.
So, we fixed what we could from our side, that is KEYW, but for the others, we must wait for a real fix in the sim.