Error: 404 Not Found

Sorry, the requested URL 'http://u.limo/wp-admin/admin-ajax.php?channel_id=social_wechat&action=xh_social_channel&tab=login_redirect_to_authorization_uri&xh_social_channel=eae32193e9&notice_str=4651875415&hash=3444842206333979d368bac9ad1db06d&redirect_to=https%3A%2F%2Fu.limo%2Ftag%2F%25E5%258A%25A8%25E7%2594%25BB%25E5%2585%2583%25E7%25B4%25A0%2F' caused an error:

Not found: '/wp-admin/admin-ajax.php'