<!-- thumbnail: https://i.sstatic.net/FrXxu.png -->
<!-- version: 1.1 -->
<!-- tag: script -->
<!-- excerpt: Convenient userscript to show a message when a answer or comment is removed when following a link  -->


###About:

When you follow a link to a comment or answer you might end-up being confused if the answer or comment is removed. 

This little userscript shows a warning on top of the page when the link you just used contains a fragment to an answer or comment that no longer exists on the page. 

*This is a repost of [my original answer](https://meta.stackexchange.com/a/251236/158100) on Meta Stack Exchange*


###Screenshot:

Here is an [Animated GIF to show the script in action][2]

###Download / Install:

You can find it ready to be consumed by TamperMonkey or GreaseMonkey on the [Github repository](https://github.com/rschrieken/SmallButHandy/raw/master/CheckForExistingCorA.user.js). 

###Platform:

The script will run on any browser that support userscripts with the general available userscript managers like Tampermonkey or GreaseMonkey.

###Contact:

If you find a bug or have a feature request either create an [issue](https://github.com/rschrieken/SmallButHandy/issues) or leave a comment here.

Allow for 6 to 8 weeks before fixing. 

###License:

The code is released under the MIT License 

###Code:

The code is written in JavaScript and has a dependency on the jQuery loaded on the page by Stack Exchange. 

For interested parties here is the full code:

    // ==UserScript==
    // @name         Check if comment and answer exist
    // @namespace    http://meta.stackexchange.com/users/158100/rene
    // @version      1.1
    // @description  Show a message if the answer or comment in the hash of the url doesn't exist
    // @author       rene
    // @match        *://*.stackexchange.com/questions/*
    // @match        *://stackoverflow.com/questions/*
    // @match        *://serverfault.com/questions/*
    // @match        *://askubuntu.com/questions/*
    // @match        *://mathoverflow.net/questions/*
    // @match        *://stackapps.com/questions/*
    // @match        *://superuser.com/questions/*
    // @grant        none
    // ==/UserScript==
    
    (function (document, window, StackExchange) {
    
        var hash = (window.location && window.location.hash)?window.location.hash:'';
    
        function showMessage(jqsel, text) {
            if (jqsel === null) {
                // wait for SE to be ready
                StackExchange.initialized.done(function() {
                    var classid = 'missing-post-or-comment';
                    // put a notify on top
                    StackExchange.notify.show('The ' + text + ' is not found. It may have been deleted', classid);
                    // remove it automagically after 5 seconds
                    setTimeout(function () { StackExchange.notify.close(classid);}, 5000);
                });
            }
        }
    
        StackExchange.ready( function() {
            if (hash.length > 0) {
                cleanHash = hash.substring(1);
                if (cleanHash.indexOf('comment') === 0) {
                    ids = cleanHash.substring(7).split('_');
                    var lnk = document.getElementById('comments-link-' + ids[1]);
                    if (lnk !== null) {
                        StackExchange.comments.loadAll(lnk).done(function() {
                            showMessage(document.getElementById('comment-'+ ids[0]), 'comment');
                        });
                    } else {
                        showMessage(document.getElementById('comment-'+ ids[0]), 'comment');
                    }
                } else {
                    if (!isNaN(Number.parseInt(cleanHash, 10))) {
                        showMessage(document.getElementById('answer-' + cleanHash), 'answer');
                    }
                }
            }
        });
    
    }(document || unsafeWindow.document, window || unsafeWindow, StackExchange || unsafeWindow.StackExchange ));

Or find it in the [GitHub repo](https://github.com/rschrieken/SmallButHandy/blob/master/CheckForExistingCorA.user.js) where you're invited to submit pull requests.


  [2]: https://i.sstatic.net/XNpge.gif