the options screen on options->addons->NPCScan is blank
typing /npcscan doesn't work either as somehow the return/enter key won't enter the command

I don't know how long this has been the case since I haven't needed to access the options lately. but recently the Expedition Scout's Pack has started screaming YOU ARE NOT PREPARED so I tried to get into the options to change it

same issue here. i just installed npcscan. i tried disabling every other addon but it's still broken.
bugsack says:

2x ...nfig-3.0/AceConfigDialog-3.0-79/AceConfigDialog-3.0.lua:1863: AceConfigRegistry-3.0-20:ValidateOptionsTable(): NPCScan.args.alertOptions.args.sound.args.channel.name: expected a string or funcref, got 'nil'
[string "=[C]"]: ?
[string "@NPCScan/Libs/AceConfig-3.0-3/AceConfigRegistry-3.0-20/AceConfigRegistry-3.0.lua"]:50: in function <...-3.0/AceConfigRegistry-3.0/AceConfigRegistry-3.0.lua:45>
[string "@NPCScan/Libs/AceConfig-3.0-3/AceConfigRegistry-3.0-20/AceConfigRegistry-3.0.lua"]:210: in function <...-3.0/AceConfigRegistry-3.0/AceConfigRegistry-3.0.lua:205>
[string "@NPCScan/Libs/AceConfig-3.0-3/AceConfigRegistry-3.0-20/AceConfigRegistry-3.0.lua"]:244: in function <...-3.0/AceConfigRegistry-3.0/AceConfigRegistry-3.0.lua:219>
[string "@NPCScan/Libs/AceConfig-3.0-3/AceConfigRegistry-3.0-20/AceConfigRegistry-3.0.lua"]:254: in function <...-3.0/AceConfigRegistry-3.0/AceConfigRegistry-3.0.lua:219>
[string "@NPCScan/Libs/AceConfig-3.0-3/AceConfigRegistry-3.0-20/AceConfigRegistry-3.0.lua"]:254: in function <...-3.0/AceConfigRegistry-3.0/AceConfigRegistry-3.0.lua:219>
[string "@NPCScan/Libs/AceConfig-3.0-3/AceConfigRegistry-3.0-20/AceConfigRegistry-3.0.lua"]:254: in function <...-3.0/AceConfigRegistry-3.0/AceConfigRegistry-3.0.lua:219>
[string "@NPCScan/Libs/AceConfig-3.0-3/AceConfigRegistry-3.0-20/AceConfigRegistry-3.0.lua"]:282: in function ValidateOptionsTable' [string "@NPCScan/Libs/AceConfig-3.0-3/AceConfigRegistry-3.0-20/AceConfigRegistry-3.0.lua"]:324: in function app'
[string "@NPCScan/Libs/AceConfig-3.0-3/AceConfigDialog-3.0-79/AceConfigDialog-3.0.lua"]:1863: in function Open' [string "@NPCScan/Core.lua"]:336: in function ?'
[string "@NPCScan/Libs/AceConsole-3.0-7/AceConsole-3.0.lua"]:94: in function ?' [string "@FrameXML/ChatFrame.lua"]:5236: in function ChatEdit_ParseText'
[string "@FrameXML/ChatFrame.lua"]:4894: in function ChatEdit_SendText' [string "@FrameXML/ChatFrame.lua"]:4930: in function ChatEdit_OnEnterPressed'
[string "*ChatFrame.xml:141_OnEnterPressed"]:1: in function <[string "*ChatFrame.xml:141_OnEnterPressed"]:1>

Locals:
(*temporary) = "AceConfigRegistry-3.0:ValidateOptionsTable(): NPCScan.args.alertOptions.args.sound.args.channel.name: expected a string or funcref, got 'nil'"

I'm having the same issue, and on the AddOns tab of the Options menu NCPScan has no options.

It doesn't look like it's been updated for DragonFlight based on a reply from the author on another issue. Also, on CurseForge the last update is Oct 31, 2020 and the game version is 9.0.1.

Probably not the best solution, but I was able to resolve by commenting out NPCScan\Preferences\Alerts.lua lines 239-252.

Edit: I also updated the embedded Ace 3.0 libs to the latest alpha version as well, in case it matters.