Custom permalinks for attachments

I’m sure the answer to this is somewhere, but I’ve searched for hours without finding it, so I apologize for asking such a basic question.

Goal
I want the permalinks for all of my attachments to format this way:
domain.com/%category%/%postname%

I would like %category% == the category of the attachment, not the category of some “Post” it is attached to

I would like %postname% == the Slug of the attachment

Status
Currently, the permalink for my attachment looks like this:
domain.com/?attachment_id=[###]

My testing page: http://www.hunterthinks.com/?attachment_id=249
[I have not completed attachment.php, so it is not pretty. header.php and footer.php should be correct, however.]

Under my current testing conditions, I want the permalink for this attachment to be http://www.hunterthinks.com/photograph/latina_19-2 (case sensitive), but that serves WordPress’s 404 page.

In the Media Library, I have added this attachment to exactly one category. It is named “Photography” and the slug is “photograph”. The category name properly displays in header.php

<h2 id="section_name">
    <?php
      if ( is_single() )
        { global $post;
          $categories = get_the_category($post->ID);
          echo '<a href="'.get_category_link($categories[0]->term_id ).'">'.$categories[0]->cat_name.'</a>';
        }
      else
        {bloginfo( 'description' );}
    ?></h2>

That makes me feel that the database understands that this attachment is in the Photography category.

In the media library, I changed the slug to “latina_19-2” merely to test if I could change the slug. Nothing happened.

No tags assigned. I’ve tried with and without caption, alt, and description. No luck.

Environment
Hosted on GoDaddy Linux Economy
I swear I saw a screen with info about the PHP and Apache version, but I can’t find it now. As I recall, both are the latest versions.

Plugins, all are the most recent, with some emphasized:

1. Advanced Custom Fields
2. Broken Link Checker
3. Facebook
4. Google Analytics for WordPress
5. Jetpack by WordPress.com; the only enabled options:

1. WordPress.com Stats
2. Spelling and Grammar
3. Omnisearch
4. Shortcode Embeds
5. Jetpack Single Sign On

• Justified Image Grid
• Media Library Assistant
• Simple URLs
• Super Socializer (problem existed before this was installed)
• Theme Check
• UpdraftPlus – Backup/Restore
• Use Google Libraries
• W3 Total Cache
• WordPress SEO
• WP Total Hacks

I have not changed anything in Yoast WordPress SEO: Permalinks. To be clear, “Redirect attachment URL’s to parent post URL.” is not checked.

Troubleshooting
I normally take notes when troubleshooting a problem, but I didn’t realize this was a problem until I had tried a bunch of things. I was sure that the issue was PEBCAK, so I just kept digging. Therefore, I don’t have a list of steps I tried. I have reinstalled 3.8.2 twice.

I have no idea if this is related, but if I am in the Media library and I edit Attachment information (such as update the Alt Text), then click update, I get the following error:

Notice: Undefined index: post_status in /home/content/h/u/n/hunterhogan/html/wp-admin/includes/post.php on line 206

Warning: Cannot modify header information – headers already sent by (output started at /home/content/h/u/n/hunterhogan/html/wp-admin/includes/post.php:206) in /home/content/h/u/n/hunterhogan/html/wp-includes/pluggable.php on line 896

It’s on a plain white screen, but if I go back to the library, all of the changes were updated.

The answer to my permalink issue might be, “It’s not possible,” which would be less than ideal, but at least I would know the answer!

Working pages
I haven’t completed all of my theme pages, but my homepage is served as a static page and the following three pages are testing pages I use. The pages work, so I feel that most of WordPress is operating as intended. (I haven’t created the category pages yet, though.)
http://www.hunterthinks.com/
http://www.hunterthinks.com/uncategorized/hello-world
http://www.hunterthinks.com/photograph/portriats
http://www.hunterthinks.com/game/creeper-world-user-space

What am I missing?
This is my first WordPress site, so I may be missing something obvious in the codex or the settings. Can someone point me in the right direction?

Thanks!