Q: Yosemite Photos iCloud photo sharing not working

Have you tried to disable the shared streams in the System Preferences, then restart the Mac, and enable them again in the System Preferences and in Photos Preferences iCloud?

It may take a few hours for the streams to populate again after resetting them this way.

I have been having the same issue, and restarting with streams turned off has not solved it.

That worked perfectly for me on both my macbook and imac. Had been having this issue since updating to 10.10.3

Hopefully Apple will iron this out, shouldn't have to jump start new stuff to get it going!

Unfortunately this did not help. I even logged off completely from the iCloud, logged in again and switched on the sharing of streams and my own photostream - no change. Strangely, Aperture on the same iMac worked perfectly with iCloud all the time, sharing streams and all.

Photos worked, once I installed Yosemite 10.10.3, but showed these symptoms after I replaced the old SSD system disk with a new one and did a recover from my Time Machine backup of the same day.

I also have this issue. I've tried disabling, the My photo stream in Photos and System Preferences, restarting, and turning back on. Nothing. Also, tried rebuilding the database, no joy.

It's an absolute joke that they release software like this to "Replace" iPhoto when iPhoto was one of the main reasons I am so far into the Apple Eco system. My photos sync between my iPhone and iPad, just not my **** MacBook with the abomination that is Photos.

I'm also having this problem. Too many bugs to use. Switching back to iPhoto.

Same thing happened to me. I was running 10.10.3 and Photo Share was working fine. Then I had a keyboard problem and restored to a backup just before the problem. This fixed the problem but Photo Share was no longer working. Clicking on the Shared tab in Photos went through the motions of connecting to the library but then eventually says 'iCloud Photo Sharing - Share photos and videos .....' with a Start Sharing Button which lets you try and create a new stream but doesn't work ... makes no mention of other streams I have access to.

At this point I should clarify that all iCloud and Photo Sharing facilities on my account are working fine on iPhone, iPad and iCloud via browser (Photos only).

Restored to a week earlier (pre 10.10.3), but still same problem. Tried turning off all iCloud activity and Photo Sharing, re-booting and enabling again. Same problem.  Logged out of iCloud on the Mac and ran with local password for a few hours then logged back in. Same Result.

Most recently I got a contact to remove me from their Photo Share and send me a new Invite. When I click on the Invite (on the Mac). I get the following pop up saying Photo Sharing is not enabled - even though everything is fully enabled.

Clearly there is a bug here for Apple to solve.

My gut instinct is that the Restore from backuo is at the root of this.

Just tried Re-Installing OS X - without wiping disc clean first. Installation went fine, but afterwards problem was still there!

I just stopped using Photos, and am back using iPhoto. The Photostream works fine through that still so I won't be using Photos any time soon. I didn't like the interface anyway.

I'm sure it'll be forced upon me soon anyway though ...

Same issue here.

Restarted, logged in/off from iCloud, enabled/disabled Photo sharing, all of them several times in different variations.

Unfortunately with no luck.

Exact same problem here.

Made a Time machine restore on a new iMac, and the Photos shared tab still stays empty.

I tried everything possible, from logging in / off from iCloud, restarting 20 times, repairing files permissions, emptying the ~/Library/Application Support/iLifeAssetManagement folder…

with no luck

This is my exact issue. Safari started acting very odd after dumping my internet history. Nothing would fix it, so I figured "Hey, i'll use that great Time Machine feature! The restore to a few days prior worked great but photos now does the exact same thing, or should I say: does NOTHING? 

When I initially started using Photos, it didn't show up either. I had to turn iCloud photos off and back on again to get it going. Since then, nothing I've done works at all.  I guess we should just wait forever for Apple to fix it. I love Apple, but they don't seem to fix issues quick enough for me.

Back to iPhoto I go.

Same issue here

I experienced the same situation with Photos after a doing a Time Machine restore to my new MacBook Pro. The photo sharing functionality was working fine on my old MacBook Pro and I double checked that all preferences settings involving iCloud are exactly the same on my new laptop. Tried disabling the streams options in System Prefs mentioned in this thread, rebooting and then reactivating the sharing streams to no avail.