iCloud photos box has a black square in it instead of a tick like the other boxes.

Greetings Kimnz4,

Thank you for using Apple Support Communities. It seems like you see a black square instead of a checkbox. This happens when not all of the Options are checked, but only some of them are. If you check the Options and they don't stay checked, try safe mode and see if the issue persists.

"Start up in safe mode

To start up in safe mode:

1. Start or restart your Mac, then immediately press and hold the Shift key. The Apple logo appears on your display. If you don't see the Apple logo, learn what to do.
2. Release the Shift key when you see the login window. If your startup disk is encrypted with FileVault, you might be asked to log in twice: once to unlock the startup disk, and again to log in to the Finder.

To leave safe mode, restart your Mac without pressing any keys during startup.

If an issue doesn't happen in safe mode

If an issue doesn't happen when your Mac is started in safe mode, try restarting without pressing any keys.

• If the issue comes back, you might have incompatible login items.
• If the issue doesn't come back, it was probably caused by a cache or directory issue with your startup disk, which safe mode fixed."

Use safe mode to isolate issues with your Mac

Please don't hesitate to let us know if the steps resolved your issue or if you need additional assistance.

Take care.