iPhone photos stopped appearing on my PC

Hi,

Until about a week ago, all of my photos taken on my iPhone 5s would appear on my PC in my iCloud Photos folder as soon as I opened the iCloud program on my PC.

Now, they do not appear any longer. I have checked every setting on the phone as well as storage capacity and no settings have been changed and there is still plenty of storage space.

The iCloud folder on the PC opens up and nothing new shows up - it just appears that they no longer load up.

Any ideas on what I might try or something I may have missed?

I had the latest version of iOS 8 until yesterday when I upgraded to iOS 9. Still, nothing happens.

Thanks.