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Troubleshooting Common Twenty Seventeen Child Theme Issues

30 threads Sep 11, 2025 Theme → Twenty seventeen

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Creating a child theme for the Twenty Seventeen theme is a best practice for making customizations that survive theme updates. However, the process can sometimes introduce unexpected problems. Based on common community reports, this guide outlines the most frequent issues and how to resolve them.

1. The "Headers Already Sent" Error and Blank Admin Screen

This critical error prevents you from accessing the WordPress dashboard and is often accompanied by a warning like: Warning: Cannot modify header information - headers already sent by (output started at .../twentyseventeen-child/functions.php:1).

Why it happens: This is almost always caused by a syntax error in the child theme's functions.php file. The most common culprits are invisible whitespace or characters before the opening <?php tag or after the closing ?> tag.

Solution:

  • Access your site via FTP or your hosting file manager.
  • Navigate to wp-content/themes/twentyseventeen-child/.
  • Edit the functions.php file using a plain text editor like Notepad++ or VS Code.
  • Ensure there is no text, space, or line break before the opening <?php tag on the very first line.
  • It is considered best practice to omit the closing ?> tag entirely to prevent this issue.
  • Save the file and re-upload it.

2. Missing Theme Options in the Customizer

After activating a child theme, the "Theme Options" panel in the WordPress Customizer disappears.

Why it happens: The Twenty Seventeen theme's options are tied to its specific setup functions. A child theme that does not properly enqueue the parent stylesheet or that has a configuration error can sometimes prevent these options from loading correctly.

Solution: First, ensure your child theme's functions.php file is using the correct method to enqueue the parent theme's styles. The recommended code is:

add_action( 'wp_enqueue_scripts', 'my_child_theme_styles' );
function my_child_theme_styles() {
    wp_enqueue_style( 'parent-style', get_template_directory_uri() . '/style.css' );
}

If the problem persists, try switching to the parent theme temporarily. If the Theme Options are still missing, there may be a configuration issue with your site's pages. Ensure you have set a static front page and a separate posts page in Settings > Reading.

3. Front Page Sections Disappear or Display Incorrectly

The content from the parent theme's front page sections vanishes when the child theme is active.

Why it happens: This is a common misunderstanding. The content for these sections is not stored in the theme's files but as theme mods in your WordPress database. These mods are specific to the theme that created them. When you first switch to a child theme, it does not automatically copy these settings from the parent.

Solution: You will need to re-enter the content for your front page sections (Services, Contact, etc.) in the Customizer while your child theme is active. The good news is that once you set them up for the child theme, they will be saved and remain there. You will not lose this work if you switch back to the parent theme and then to the child theme again.

4. Custom Templates or Page Content Not Displaying

Custom page templates don't work on the static homepage, or page content shows raw code instead of a rendered page.

Why it happens: For custom templates on a static homepage, WordPress can sometimes be particular. If a page file in the child theme (like page.php) is missing critical WordPress loop functions, it can fail to display content properly.

Solution: If you have copied a template file from the parent theme to your child theme to modify it, double-check that you have not accidentally removed essential WordPress functions like the_content() or the main WordPress loop. For a custom homepage template, ensure it is correctly named and that the template header comment is included at the top of the file.

5. Correctly Enqueuing Stylesheets

There is confusion about the right way to load the parent theme's CSS.

Solution: The safest and most reliable method is to use the code snippet provided in Solution #2 above. While you may see references to using a handle like 'twentyseventeen-style', the simple method of using get_template_directory_uri() to target the parent theme's directory is effective for most use cases.

By methodically working through these common pitfalls, you can successfully create a stable Twenty Seventeen child theme and build upon a solid foundation.

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