Hi there, New Mac user so please bear with me. I've had an iPhone/iPad for a while so have been successfully using iCloud Photo library for some time. Recently I purchased a Mac and started using it's Photos app. My existing library downloaded just fine however I imported 350-ish photos from a USB and they won't upload to iCloud. They are permanently stuck and it says 'uploading x photos' at the bottom of the photos tab. I have a 15" MacBook Pro (mid-2015) running OS X Yosemite (10.10.5). I have logged out and in, I have rebooted, I have unticked iCloud Photo Library and on again. Any suggestions to get this working? Thanks in advance!