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Troubleshooting Common Twenty Twelve Theme Issues: From H1 Tags to Character Encoding

34 threads Sep 9, 2025 Theme → Twenty twelve

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As a long-standing default WordPress theme, Twenty Twelve is known for its stability. However, like any software, users can occasionally encounter bugs or unexpected behavior. This guide compiles solutions to some of the most frequently reported issues based on community discussions.

1. Multiple H1 Headings and SEO

The Problem: SEO analysis tools flag that your pages have two H1 headings: one for the site title and another for the page or post title. This can be perceived as a negative SEO practice.

The Solution: The Twenty Twelve theme intentionally uses an H1 for both elements. To change the site title's H1 to another heading tag (like H2), you must create a child theme. Copy the header.php file from the parent theme into your child theme's directory. Then, locate the <h1> tags surrounding the site title and change them to your preferred tag, for example, <h2>. This modification ensures your change persists after theme updates.

2. Special Characters Displaying Incorrectly

The Problem: Special characters, such as the micron symbol "µ", display correctly in post content but are corrupted in the navigation menu, appearing as a different character (e.g., "M").

The Solution: This is often a character encoding issue. Ensure your site and database are using UTF-8 encoding, which supports a wide range of characters. You can typically configure this in your wp-config.php file with the line define('DB_CHARSET', 'utf8');. If the problem persists, try manually re-typing the character directly into the menu management screen in the WordPress admin area.

3. Image Dimension Display Bug

The Problem: On image attachment pages, the image metadata (dimensions) does not display correctly. Instead of showing "1221x124", it may only show "x". This bug was identified in WordPress 5.6.

The Solution: This is a confirmed bug introduced by a core WordPress update. The issue is not with the Twenty Twelve theme itself but with how it interacts with a change in the core software. The solution is to wait for an update to either WordPress core or the Twenty Twelve theme that patches this compatibility issue. Keeping your installation updated is the best way to resolve this.

4. Plugin and Browser Conflicts

The Problem: Features work in preview mode but not when published, or certain elements only break in specific browsers (like Chrome). Other users report PHP warnings related to specific plugins, such as Polldaddy.

The Solution: Conflict testing is a crucial troubleshooting step.

  • Plugin Conflicts: Deactivate all plugins. If the problem resolves, reactivate them one by one to identify the culprit. A common fix for plugin-related errors, like the twentytwelve_wp_title() warning, is to ensure all your plugins and themes are updated to their latest versions.
  • Browser Conflicts: If an issue is isolated to a single browser (e.g., Chrome), try clearing the browser's cache and cookies. The problem could also be caused by a browser extension; try disabling extensions to see if that resolves the display issue.

5. W3C Validation Errors (hgroup)

The Problem: The W3C validator flags an error because the theme uses the obsolete <hgroup> HTML5 element.

The Solution: The hgroup element has been officially deprecated from the HTML specification. While this validation error does not affect how your site functions in browsers, it can be fixed by modifying the theme's files. This requires creating a child theme and editing the relevant template file (likely header.php) to replace the <hgroup> tags with a more modern element like <div> or a structured <header> element.

When modifying any theme, it is highly recommended to use a child theme. This ensures your customizations are not overwritten when the parent theme receives an update for security or compatibility.

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