[zo_zo65im]

I run OS X Yosemite V10.10.3 on a new iMac. If I click on Systems Preferences and then on iCloud, my Photos option remains checked for only a limited time before unchecking itself. Furthermore, all the photos have not sinced accross all my devices in spite having more than 16GB available. Any suggestion of how to remedy this?

[Bigeric23]

Do you have all three boxes checked under options?

[zo_zo65im]

Yes indeed I have

[Bigeric23]

Yes indeed I have

Give this a try:

1) Uncheck the last box (iCloud Photo Sharing)

2) Click Done

3) Go back to Options

4) Check last box

5) Click Done

[zo_zo65im]

Tried your recommendation, however Photos continue to uncheck itself

[Bigeric23]

Tried your recommendation, however Photos continue to uncheck itself

Have you verified the iCloud Photo Library option under Preferences is selected in the Photos app, too?

[zo_zo65im]

Yes indeed and all the options are checked

[Bigeric23]

Yes indeed and all the options are checked

Well, I hope someone else has a solution for you. But apparently you are not alone:

https://discussions.apple.com/thread/7039993

[zo_zo65im]

Thank you for your kind endeavors. If I go to Photos preferences (icloud) , the following are ticked:
ICloud photo library
Download originals to this Mac
My photo stream
ICloud photo sharing

In my own endeavors I played around with the button next to the iCloud Photo library marked "Pause for one day" by clicking on it, the writing fades and I do not know if syncing is then temporarily stopped for one day or not in this position. This action however stopped photos from unchecking itself as per the original problem identified. Having this "paused for one day" button faded or not faded, the iCloud library still reflects "downloading 1868 photos" with this figure not decreasing if the button is in its faded or not faded position. May be a stupid question, for downloading to occur, must this button be faded or not?

[Bigeric23]

Thank you for your kind endeavors. If I go to Photos preferences (icloud) , the following are ticked:
ICloud photo library
Download originals to this Mac
My photo stream
ICloud photo sharing

In my own endeavors I played around with the button next to the iCloud Photo library marked "Pause for one day" by clicking on it, the writing fades and I do not know if syncing is then temporarily stopped for one day or not in this position. This action however stopped photos from unchecking itself as per the original problem identified. Having this "paused for one day" button faded or not faded, the iCloud library still reflects "downloading 1868 photos" with this figure not decreasing if the button is in its faded or not faded position. May be a stupid question, for downloading to occur, must this button be faded or not?

If you select that option it will pause synching, which is faded text.

[zo_zo65im]

I run OS X Yosemite V10.10.3 on a new iMac. If I click on Systems Preferences and then on iCloud, my Photos option remains checked for only a limited time before unchecking itself. Furthermore, all the photos have not sinced accross all my devices in spite having more than 16GB available. Any suggestion of how to remedy this?

I have since as ertained that I am not alone in this: see also https://discussions.apple.com/thread/7039993. The problem does not occur on my Mac Mini, where photos works seamlessly. I am re-posting this in the hope that someone with a similar problem that was solved could assist