Yesterday, I purcchased and installed Lightroom 6 on my MacBook Air with the latest IOS X. I have over 20 thousand photo files in Apple's Photos, library size is 54.4 GB. I can't import any photos into Lightroom. In the nvaigator it shows various folders but claims "no pictures found."
Outside Lightroom, in the Mac Finder, I see the Photos library, it's size, the older iPhoto and Aperture libraries. I can normally browse all my photos, projects, events, smart events via Photos App. But I cant figure out how to import all my photos into Lightroom.
There's a plugin for import images from Aperture & iPhoto to Lightroom Refer: Aperture import plugin now available
But if you are using Photos, then there no plugin for it, you need to export out the Images from the Photos and then import it from there in Lightroom.
Let us know if that helps.
Determine the folders in which Photos is storing photos (using Show Package Contents) and then import those folders into Lightroom using Import Photos and Videos under the file tab.