3 referenced files in your library will not upload to iCloud Photo Library error Select referenced files in your library and choose “Consolidate” from
  the File menu to copy the original files into the library.


I get the following error messages when I try and sync my Photos Library on my mac with iCloud and then it just says 'Updating' indefinitely.

Does anyone know how to fix this? I have selected all files and click Consolidate and it says 'No files to consolidate'
I solved this problem by looking for all the filenames prefixed with "Copy - " and deleting them.