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=6568ad74fd&notice_str=5191975144&hash=7fc48d7c49e04ee5f7f707ee1b4e7e6b&redirect_to=https%3A%2F%2Fu.limo%2Ftag%2Flogo%25E5%259B%25BE%25E7%2589%2587%25E5%25AA%2592%25E4%25BD%2593%2F' caused an error:

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