For the past two years, VCS clients were supposed to be using an API key instead of CurseForge credentials since CurseForge was switched over to using Twitch accounts and its own authentication system was decommissioned.
Early in April, every bit of the old authentication code was removed from the sites which brought to light the fact that in some cases the old credentials had been erroneously accepted. To fix this, go to the site your projects reside on and click your name on the top navigation bar. On the dropdown, select "My Account" and on the next page click into the My API Tokens tab. From there you'll be able to generate a new API token which you would use as the password in your VCS client.
Blizzard has made this impossible with the launch of Mists of Pandaria. When they introduced vignettes, the old cache system went away and none of the previously-existing rares were updated to use that system.
What I've done, personally, is turn on nameplates and set them to always show. Another option is to use a targeting keybinding, which you'll find under the WoW client's keybinding menu. Unfortunately, that entails constant key-mashing.
Which NPCs is this happening with? If they're older NPCs which aren't tied to an achievement or have no tracking quest, the only thing you can do is manually ignore them. If they aren't either of these, that means they're missing attribution.
When the targeting frame appears, you can hover over the X button on it and you should see the option to ignore via right-click.
Just want to chime in and say to please not contact us; projects are the sole responsibility of their owners, and we will not transfer them under any circumstances. We used to do so if there hadn't been updates in a couple of years and the license allowed for forks, but we ended that practice roughly three years ago after a rash of folks came back to find they no longer controlled their own project.
Not only can I not reproduce this, but I can't fathom how this would even be possible since NPCScan doesn't touch trade skills at all. Please install BugSack and try again - you should get a Lua error when you cannot open your profession window, which will tell you what and where the error occurs.
The new range is intentional, and is more in-line with the behavior pre-MoP when deleting the cache was a thing. When Blizzard took this away, everyone lost their minds because they were restricted to nameplate and minimap range. Now that BfA has changed things yet again to allow for longer-range detections, that is being complained about. There's no winning!