Genuine Arduino? This board comes from an uncertified manufacturer. We won’t be able to provide any support if it doesn’t work as expected.

Here is the situation. You have bought what you believe is a genuine Arduino.

You download the new IDE software and when you plug the Arduino in you get a pop-up which says;
“This board comes from an uncertified manufacturer. We won’t be able to provide any support if it doesn’t work as expected.”

Stop ! Don't Panic!
The good news is you do have a genuine Arduino board    - sort of

Analogy-
There are two nerds at school, (lets call them, Archibald, he's from the US and Luigi, he's from Europe). They look set to become the best in class, and they have managed to avoid being bullied for years. Looking Good!
Upset with this lack of being picked on by the lesser kids, they decide to bully each other!, and go at it like Popeye and Brutus. Not so Good!
While they are beating each other up, new nerd on the block (let's call her Rosie Berry Pi) puts on a spurt and sneaks in to win the prize, lucky Rosie!
Rosie is showered with the adulation of the whole school. Meanwhile Archie and Lui are reduced to glaring at each other in detention. Silly boys.

What's really going on
I will try and be brief.
Arduino LLC was formed by the big 5 (Massimo Banzi, David Cuartielles, David Mellis, Tom Igoe and Gianluca Martino) in 2009. These are the "Code Guys", and have been creating and directing the software that makes it all work. The run the site Arduino.cc, where most people get the Arduino IDE software from. The manufacturing of the Hardware side was undertaken by "Smart Projects" and after a couple of twists it is now called Arduino SRL, they run the site Arduino.org
Both teams believe they are the "Real" Arduino, and are currently in litigation with each other.
Arduino LLC(the Euro lot) have fired a salvo at Arduino SRL (the Yanks) by including a pop-up in the software which detects the versions made for Arduino SRL. Is this a targeted attack specifically at the yanks? I would suggest it is, as the pop-up is oddly absent if you use one of the obviously fake chinese clones.

When the dust settles, will Arduino triumph in its SRL or LLC form? or will the brand reputation be damaged enough to let the new guys take the market lead?

My suggestion, just tick the box that says "Don't show me again"