Finally got around to post this error. Installed Version: 5.2.1 Alpha 2 after I removed the prior beta version, even wiped the SV's. As seen by BugGrabber, enUS client. This happens when I log in any toon.
12x _NPCScan.Overlay-5.0.0.3\Modules\Carbonite-5.2.1.lua:13: attempt to index global "NxData" (a nil value)
_NPCScan.Overlay-5.0.0.3\Modules\Carbonite-5.2.1.lua:13: in main chunk
Locals:
In addition to NPCScan and NPCScan Overlay I also use _NPCScan.Overlay.Broker on
http://www.curse.com/addons/wow/npc-ov-ldb . Not sure if it has anything to do with it but tossing it in for sake of completeness.
I also wiped the old NPC files along with their SV's and reinstalled the files fresh.