there was a problem deregistering this iphone with icloud

hi...

i have big problem with this

i have iphone 6 plus...i did mistake and i created new icloud account with my phione and i forget to active it but i inserted inside of my iphone..

the find my iphone is on..

now i activated my icloud account but it tell my no device connected but it is still in my iphone and when i want to sign out

from my phone it tell me :

there was a problem deregistering this

iphone with icloud.

try deleting your account again

.

what can i do with this?

i want to restore my iphone to latest version and i have this trouble.