추가로 질문내용의 오류는 헤더부분의 인자가 배열인수가 아니라 발생된 오류입니다.

$ch = curl_init();

curl_setopt( $ch, CURLOPT_URL, "https://nid.naver.com/oauth2.0/token");
curl_setopt( $ch, CURLOPT_POST, true);
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt( $ch, CURLOPT_POSTFIELDS, "grant_type=authorization_code&client_id={$config[naver_client_id]}&client_secret={$config[naver_secret_key]}&code={$_GET['code']}");
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);

$result = curl_exec($ch);
curl_close($ch);
$R_value = json_decode($result);


토큰을 받는 부분이여서, 말씀대로 CURLOPT_HTTPHEADER,0 부분을 삭제처리 하였습니다.

"토큰 오류입니다" 라는 오류를 계속 뿜네요...

도움 부탁드리겠습니다 ㅜㅜ..

===========아래 소스코드 첨부합니다==============================

if($_SESSION[state]==$_GET[state]){

$ch = curl_init();

curl_setopt( $ch, CURLOPT_URL, "https://nid.naver.com/oauth2.0/token");
curl_setopt( $ch, CURLOPT_POST, true);
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt( $ch, CURLOPT_POSTFIELDS, "grant_type=authorization_code&client_id={$config[naver_client_id]}&client_secret={$config[naver_secret_key]}&code={$_GET['code']}");
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);

$result = curl_exec($ch);
curl_close($ch);
$R_value = json_decode($result);

$access_token = $R_value->{'access_token'};///access token
$expires_in =$R_value->{'expires_in'};//////토근 만료시간

if(!empty($access_token) && $expires_in>0 && !empty($expires_in)){

$headers=array("Authorization:Bearer $access_token","Content-Type:application/x-www-form-urlencoded;charset=utf-8");

$url="https://apis.naver.com/nidlogin/nid/getUserProfile.xml";

$ch = curl_init();

curl_setopt( $ch, CURLOPT_URL, $url);
curl_setopt( $ch, CURLOPT_HTTPHEADER,$headers);
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);

$result = curl_exec($ch);
curl_close($ch);

$xml = simplexml_load_string($result, 'SimpleXMLElement', LIBXML_NOCDATA);

foreach ($xml->result as $value){
$result_code=$value->resultcode;
}
if($result_code=="00"){////00이면 성공
foreach ($xml->response as $value){
$email =  $value->email;
$name= $value->name;
$mid= trim($value->id);

}
//회원아이디 세션 생성
$member = get_member($mid);

if(empty($member[mb_id])){/////카카오톡 에 받은 고유키값을 비교 없으면 회원으로 등록시킨다.
$sql="insert into g5_member (mb_id,mb_password,mb_nick,mb_name,mb_email,mb_level,mb_datetime,mb_open_date)values('$mid',password('$mid'),'$name','$name','$email','{$config['cf_register_level']}','".G5_TIME_YMDHIS."','".G5_TIME_YMD."')";
mysql_query($sql);
}
set_session('ss_mb_id', $mid);
set_session('ss_mb_key', md5($member['mb_datetime'] . $_SERVER['REMOTE_ADDR'] . $_SERVER['HTTP_USER_AGENT']));

echo"<script>opener.location.href='/';window.close();</script>";

}else{
echo"<script>alert('파싱 오류 입니다.');window.close();</script>";
}

}else{

echo"<script>alert('토큰 오류 입니다.');window.close();</script>";
}
}else{///인증실패

echo"<script>alert('인증 오류 입니다.');window.close();</script>";
}
?>