Cannot sync my iPad 4 on iTunes

Hello,

I do not speak English, excuse my bad ticket ....

IL a few days ago I tried to connect my iPad 4 generation system update my Mac OSX El Capitan, system day also.

the icon of the iPad is briefly appeared on iTunes then quickly disappeared. iTunes sent me the following message: "iTunes can not read the iPad content Teiki Go to the Summary tab of the preferences of the iPad and click Restore to restore the original settings for this iPad.".

This is the first time I encounter this problem. I said that my iPad is not jailbroken I am not a follower of these techniques.

if you can send me a tutorial to get out of this impasse that would help me.

Thanks in advance

cordially

iPad 4 WiFi + 3G