Could you help me please how can I solve this?
Hi Saeed,
do you use a test install or a purchased one, or hacked one, because you are not marked as customer?
You use your own translation. This leads to the assumption that only a small error in the language file has triggered this problem.
On your side I would check the lang file around wcf.user.avatar.error.disabled.
Perhaps you have disabled the avatar and it's only a configuration error.
Translation of this software is not easy, you always have to look close to the "Code and its function" and take care to leave the code intact.
Good luck