iCloud photo library is not downloading all images to my Mac or iPhone

Hi Léonie - thanks again for your suggestions. I tried downloading one of the ‘blank’ images from Photos on my Mac and it came up with an error:

Then:

However, when I found that exact image on the Photos app within iCloud website in Safari, it downloaded fine and opened up in Photoshop with no issues. It is evidently a problem with syncing rather than the image itself. How can I make it download the original. It seems to be saying it cannot connect to the internet to download the original, but that is nonsense as I immediately after downloaded it from iCloud website ...

This is a screen shot of my Photos screen (ignore the one photo that actually is previewed; my question is about all the others). This is the default view in Photos so called "Photos" at the top of the navigaton panel on the left. All of the missing photo previews DO appear in my iCloud.com Photos. And at the bottom of this screen, you will see a message that seems permanent: "Downloading 233 images". (Isn't it amazing that I have 77,183 photos!? About a third of those are duplicates and that's part of my question.) Where is the reference copy of each image stored? If it's stored in iCloud and I am deleting images in Photos on one Mac, will the deletion be synced back to iCloud? (But right now that sync seems broken, so it's hard to trust it either direction!) If is broken, how do I fix it? This happens on my other two Macs (Macbook Air for travel and iMac at work) as well, so I am getting really confused abut where my photos are actually stored and whether, if I delete on one computer, I won't be accidentally deleting more than one copy!

Where do I go to get definitive information about this?! I'm even willing pay to get this solved because I can't really use my photos in this state.

If the photo are all readable at www.cloud.com, you could try to start over with a new Photos Library. Create a new, empty Photos library and make it your system Photo Library and enable iCloud Photo Library for it. Then all photos will download from iCloud to this new library. If you do not have enough free storage on your internal drive, create the new library on an external drive, or move your current library to an external drive to make space for the new library.

Use multiple libraries

Starting with a new library will restore your current library from iCloud, but one drawback will be, that all faces thumbnails will be missing. You will only have the searchable faces tags left. Use Photos and iCloud Photo Library on multiple Mac computers - Apple Support

Do you have "Optimize Storage" enabled on you iPhone or your Mac?

Have you checked, it the photos actually have been uploaded to iCloud? Open the Photos.app at the iCloud web interface www.cloud.com and check, if the photos in question are showing the same problem in iCloud.

Added: I am seeing the white rectangle with the cloud icon, whenever I edit a photo. The icon goes white, until the edited version has been uploaded to iCloud and synced back. If you are seeng many of these cloud icons a large prt of the library is not yet in sync.

Is there a progress bar in the iCloud Preferences on your Mac?

Have you checked, if these white thumbnails are duplicates of photos you are having twice in your library? Look at the Info panel to see the filename. Then search for this filename, to see if you are having a second version.

The photos are all there via the iCloud website. I have tried various tricks that I have read online to try and get it to re-sync on my iPhone, iPad and Mac, but nothing has worked

Download them from the iCloud website to a folder and check the photos, if there is something problematic with them. Try to reimport a few of them to your Photos Library.

Nigel, rebuilding the library is usually a good idea, but if the library is an iCloud Photo Library, I would only use it as the last resort, because after a rebuild, the complete library will start to upload again to iCloud, and in his case, the upload doess not seem to work. I would be reluctant to try it.

Photos is probably using different servers than the web interfaces to iCloud. Do you have any antivirus software or firewalls enabled, like kaperski?

can you connect to other services, like the iTunes Store or App Store? To Facebook?

Hiya - I only have the built-in OSX firewall turned on. However, I am having the same issue with the same images on my iPhone and iPad, not just my Mac. The web interface is the only place I can see them. Surely there must be a way to trigger a sync manually in this scenario?

If it's stored in iCloud and I am deleting images in Photos on one Mac, will the deletion be synced back to iCloud? (But right now that sync seems broken, so it's hard to trust it either direction!)

The deletion will sync back, if you let Photos delete photos in a Photos library , that is syncing with iCloud Photo Library. So deleting single photos from your library using photos will delete them from iCloud. So you first need to download the photo from iCloud, using the web interface, and then delete the broken version from your Photos library.

But if you simply starter with a new, empty library and make it your iCloud Photo Library, all photos will download to that new library and you can delete the old library, that is no longer syncing with iCloud. Only one library at a time can sync with iCloud.

Thanks again - but I was hoping there was a way just trigger a new sync as I don’t want to create a whole new library file and have to re-download thousands of images as it seems risky. Maybe I will just have a quick guess as to how many are ‘broken’ and download them from iCloud and import them to Photos one by one if there are not too many?

I wish there were a way to trigger a new sync. If you import new photos, edit photos, or delete photos it will try to sync the chances, but just queue these requests until the current sync has been accomplished. if you do not want to start over from scratch the images files that re blocking the sync need to be removed from the library.

OK: Here is the strangest thing I've seen in a while. I do not generally use Apple Mail; instead I use Microsoft Outlook for Mac. (Don't ask; that's a whole other conversation.) But a couple of days ago, I opened Apple Mail for the first time in months -- and automagically all of the photos that were not downloading to the Photos client started downloading. I didn't change anything, except launching Apple Mail and syncing my message from the server. And I now have 77,427 photos in my local Photos library. Why does opening Apple Mail make the Photos sync with iCloud work? Lord knows; one of the mysteries of the Apple Universe. 😕

I have had this problem - in my case it was just missing thumbnails. Have you tried repairing the Photos library.

Information here: Photos for OS X: Repair your library