iCloud doesn't work

Hi everyone,

I've got a problem with iCloud backups, I saw that iCloud backups were disabled for more than 2 weeks. i went in the Settings to active the automatic backup but it doesn't work 😢, when I click on the interruptor to activate it, i've got a "Enabling Backup" message and then the app "Settings" crash to the springboard. As you can see in the following picture : (You can also check that i've got more than 1Gb Free in iCloud)

Please note that : i've already reboot the device, already restore with iTunes, (Downgrade from iOs 8.0 3rd Beta) to iOs 7.1.2) as a new iPhone

Waiting for your answers,

Sincerely yours

dr-lu74

PS : I would apologize if you found any mistakes, but i'm French 🙂