Spoiler warning: I don't have a fix for this yet. So if you're coming here from Google hoping that I have the answer to your problems, I don't. I'm merely documenting it here so that someone who does have the answer might stumble across it and leave a comment with the solution. If a hero does arrive, I'll remove this. Leaving a comment below should allow you to be notified of future updates. This also isn't a post about the beta of iCloud Photo Library. This is on iOS 8.3.
Update 2015-06-30: I upgraded to iOS 8.4 today and am still seeing the same issue. Now up to 363 Items to Upload.
I've gotten the "iCloud Photo Library Has Not Updated in x Days - Connect to WiFi to update." error for, as of this post, 21 days. And of those 21 days, I've been on WiFi pretty much non-stop.
That this official error message doesn't show up in Apple support anywhere [footnote]At least in my Googling it doesn't. I'd love to be proven wrong here.[/footnote] likely means very few users are experiencing it - or that they're not vocal enough to Apple about the error.
Things that could be going on:
- A very large video file that's trying to upload but keeps stalling out when I leave WiFi areas. (Unlikely since I'm usually home on WiFi for at least 12+ hour stretches.)
- A corrupt image file that's unable to pass whatever error checking Apple has to make sure photos are uploaded properly. (Could be but there's no status/error message to show otherwise.)
- Apple has blocked my iPhoto Library from updating. [footnote]Grasping at straws here. Maybe Tim Cook doesn't like my kids?[/footnote] (iPhoto Library on my iMac and MacBook Air are in sync and I'm able to add photos that way.)
Or any number of other things could be happening but there's no way to know because "It Just Works™" so why bother exposing more detailed information to a user for troubleshooting, right?
- Turning off and turning iCloud Photos. It seemed to work and photos started uploading again. But eventually I got back to this same spot. [footnote]Warning: If you've started uploading to Flickr via their great iOS app while trying to sync your iCloud Photo Library, this creates a bunch of duplicate photos in that library. So now I have 36,539 photos to upload to Flickr before they're in sync. Hashtag duplicate photo hell.[/footnote]
- Restarting my iPhone. Yes. Thanks to iOS 8.3's penchant for rebooting during app updates I've restarted my iPhone many times.
- Random WiFi issues. My router's been restarted. I've been on other WiFi networks for long enough to start an iCloud update I'd think.
So for now I'm stuck seeing that wonderful overlay once a day reminding me to get on WiFi and the constant status update at the bottom of my iPhoto library reminding me how many photos aren't actually backed up to iCloud. [footnote] 104 items to upload as of this post. [/footnote]