Page works when called directly, not when using menu link

Oh bummer, I missed the part where you said, “When I enter the URL directly or click the link in the editor the About page loads fine. ‘About’ is a custom page design which, from what I can tell, seems to be coded fine.”

Hmm, as I stated above when I go to http://www.therockingchair.org/about I see the same “This XML file does not appear to have any style information associated with it. The document tree is shown below.” issue you originally reported. That is, I did not have to click the About link on your home page. As for the About page being a custom design, might I suggest showing the current output to the page’s designer and see what they have to say?

P.S., Has the About page ever worked? And, if so, when did it break? And between those two times, did you update WordPress, your plugin(s), and/or your theme?

Okay, so ALL plugins disabled and your trouble remains. But, if you activate one of the default WordPress Twenty series themes rather than your current “The Rocking Chair” theme then the issue is no longer reproducible, right?

Is the theme’s creator the same person that coded your About page? Because it’s obviously a theme related issue you are having being that a default theme fails to reproduce the issue. If not, then you might need to find someone else that can take a wider look at your theme to see what’s going on with your About page as well as, possibly, other issues.

P.S., When reporting this bug here or elsewhere just say:

Steps to reproduce:
1. Go to http://www.therockingchair.org/about

Result:
User taken to page that stated, “This XML file does not appear to have any style information associated with it. The document tree is shown below.” and:

<playlist version="1">
<trackList>

<track>
<title>Front Door</title>
<creator>Jason</creator>
<location>http://www.therockingchair.org/about_photos/doors_lg.jpg</location>
<info>http://www.therockingchair.org</info>
</track>

<track>
<title>Open Front Door</title>
<creator>Jason</creator>
<location>http://www.therockingchair.org/about_photos/opendoor_lg.jpg</location>
<info>http://www.therockingchair.org</info>
</track>

<track>
<title>Inside the Door</title>
<creator>Jason</creator>
<location>http://www.therockingchair.org/about_photos/insidedoor_lg.jpg</location>
<info>http://www.therockingchair.org</info>
</track>

<track>
<title>Inside Room</title>
<creator>Jason</creator>
<location>http://www.therockingchair.org/about_photos/room1_lg.jpg</location>
<info>http://www.therockingchair.org</info>
</track>

<track>
<title>The Fireplace</title>
<creator>Jason</creator>
<location>http://www.therockingchair.org/about_photos/fireplace_lg.jpg</location>
<info>http://www.therockingchair.org</info>
</track>

</trackList>
</playlist>

Expected result:
Expected properly formatted HTML page.

Reproducible?
Always

Occurs:
– Mac Firefox 46.0.1
– Mac Chrome 50.0.2661.94 (64-bit)
– Win Edge 25.10586.0.0
– Win IE 11.212.10586.0

OK I’ve looked at your header code, and whomever wrote that Theme code is using a *very, very* old method for the sub-menu ‘drop down’ effect.

The reason it happens only on your top-level “About” page and not it’s sub-pages is that old script method is applied *only* to that one link, as so:

<a class="about" title="About" href="#" onmouseover="mopen('m2')" onmouseout="mclosetime()" class="small">about</a>
                  <div id="m2" onmouseover="mcancelclosetime()" onmouseout="mclosetime()">

BUT the good news is that the same effect can very easily be achieved with CSS and by using the “Custom Menus” function in WP (Appearance>Menus) *provided that your Theme supports custom menus* and it provides the necessary CSS (most Themes these days do).

I could not tell from looking at your header code exactly what theme you are using, it looks custom OR whomever wrote it changed the name to match your domain…but you have two choices:

A. Easiest – just go to the Theme repository and select a new Theme. You can still add your custom logo and fonts, and if you really want that garish background you can add it in the CSS for the body tag.

B. Trickier – add custome menu support and the necessary CSS to your existing Theme.

If you go with option B, there are 4 steps:
1) Add some code to your functions.php file:
a) add theme support for menus:
https://codex.wordpress.org/Function_Reference/add_theme_support
b) register a nav menu:
https://codex.wordpress.org/Navigation_Menus

2) Add the menu location to your header.php file where you want it – it would replace your current block of code that starts out with <ul id="sddm"> (and ends with the next) </ul>
How to do this is on the same page as registering your menu, look for the section labeled “Display Menus on Theme”

3. Add some styles to your CSS stylesheet (styles.css) – here’s a great tutorial:
http://line25.com/tutorials/how-to-create-a-pure-css-dropdown-menu

4. Lastly, just go to Appearance>Menus and design your menu how you like it – create a menu, check the pages you want in your menu, click and drag them into the order you want (you’ll notice that offsetting them slightly to the right creates your submenus), then assign it to your new menu location, and Save it.

If you decide to go this route, be SURE to backup everything first, most importantly the three files you’ll be modifying – functions.php, header.php, and styles.css. I also recommend testing this on a sandbox or staging installation first, particualarly if your site gets a lot of traffic and you don’t want site visitors seeing any wonkiness while you’re setting this up.