Trouble with Syncing iCloud Photo

Yesterday for no apparent reason, I received this error on my iCloud Photos. I don’t sync my iCloud photos to my Mac, only my Photo Stream, but this is error I received.

iCloud Photos is only available on macOS Standard, macOS Extended and APFS formatted volumes.

My Mac’s hard drive is a formatted APFS, so I didn’t know what do next.

After a Google search, I found this website with the solution.

MacRumors website

MrGimper said:
OK. This is what I did, but I caveat it with the fact that I have no idea what else this may mess up. I know it will delete all passwords you have stored in keychain, and I read that it could stop access to secured/private notes if you use them.

Launch "Keychain Access" via spotlight search
Ensure "login" is selected in the left pane under "Keychains"
In the "Keychain Access" menu, select "Preferences"
Click "Reset my Default Keychain", and follow what it asks you to do to confirm.
Reboot and then try iCloud again.
Done. Worked perfectly, I finally got logged in!

Basically, in your Keychain > Preferences, you will find this option. Click it and restart.

After logging back into iCloud (and a bunch of other services) and resetting my iCloud Photo sync preferences, I was able to get my Photo Stream working.

Hope this helps!