HideYahooMailAdBlockPopUp.user.js

// ==UserScript==
// @name         Hide Yahoo Mail Ad-Block Pop-Up
// @description  Hides the annoying ad-block pop-up in Yahoo Mail
// @version      1.0.0
// @author       heavyLobster2
// @namespace    github.com/heavyLobster2
// @downloadURL  https://gist.github.com/heavyLobster2/bf16d9e7050145f9cda9384fa3a6dcf3/raw/HideYahooMailAdBlockPopUp.user.js
// @match        *://mail.yahoo.com/*
// @grant        none
// ==/UserScript==
(function () {
    "use strict";

    var removePopup = function () {
        var popups = document.querySelectorAll("#modal-outer");
        for (var i = 0; i < popups.length; i++) {
            var popup = popups[i];
            if (popup.getAttribute("aria-labelledby") === "adblock-whitelist-cue") {
                popup.remove();
            }
        }
    };
    removePopup();

    (new MutationObserver(removePopup)).observe(document, { childList: true, subtree: true });
})();