Just got my sparkly new Raspi 3. Moved the working Motioeyeos SD card from my Raspi 2 to the 3, and all I get is a colourful square on the screen. Moved the card back to the 2 and all worked fine. Back to the 3 - pretty square again.
I've downloaded Raspbian (Wheezy or Jessie - I forget ) and that works fine on the 3, but oh the drama to stream video, hence the desire to use Motioeyeos.