Make sure you have Device OS 5.3.2 or later (5.6.0 recommended). It looks like you're targeting an older version of Device OS. It also now occurs to me why the example build failed - it was tested with 5.0.1 which does not support P2 NeoPixels.
Make sure you have Device OS 5.3.2 or later (5.6.0 recommended). It looks like you're targeting an older version of Device OS. It also now occurs to me why the example build failed - it was tested with 5.0.1 which does not support P2 NeoPixels.