Five Common Wordpress Theme Errors and How to Fix Them

As a WordPress developer, you are going to face theme errors from time to time.

If you’ve already followed our WordPress Developer Guide then you may have already encountered some of these problems but what do you do when you get stuck?

In this post, we’ll explore five of the most common WordPress theme errors and provide solutions to help you resolve them quickly.

1. White Screen of Death (WSOD)

The White Screen of Death is one of the most dreaded WordPress errors, where your site displays a blank white page with no error message.

Cause: This often occurs due to a PHP error, exhausted memory limit, or plugin/theme conflicts.

Solution:

1. Enable WordPress debug mode by adding this to your wp-config.php file:

   define( 'WP_DEBUG', true );
   define( 'WP_DEBUG_LOG', true );
   define( 'WP_DEBUG_DISPLAY', false );
   

2. Check the debug log in wp-content/debug.log for specific error messages.
3. Increase PHP memory limit in your wp-config.php file:

   define( 'WP_MEMORY_LIMIT', '256M' );
   

4. Deactivate all plugins and switch to a default theme to isolate the issue.

2. Broken Layout After Theme Update

Sometimes, after updating a theme, you might find that your site’s layout is broken or elements are misplaced.

Cause: This often happens due to changes in the theme’s CSS or structure that conflict with your customizations.

Solution:

1. Check if you’ve made any custom CSS changes and reapply them.
2. Update child theme if you’re using one.
3. Clear your browser cache and any caching plugins.
4. Use a tool like WP Rollback to revert to the previous version temporarily.

3. Fatal Error: Cannot Redeclare Function

This error occurs when a function is defined more than once in your theme or plugins.

Cause: Multiple declarations of the same function, often due to copy-pasting code or conflicts between theme and plugins.

Solution:

1. Use function_exists() check before declaring functions:

   if ( ! function_exists( 'my_theme_setup' ) ) {
       function my_theme_setup() {
           // Function code here
       }
   }
   

2. Use unique prefixes for your function names to avoid conflicts.
3. Check for duplicate function declarations in your theme files.

4. Sidebar Below Content

Sometimes, your sidebar might appear below the main content instead of beside it.

Cause: This is often due to CSS issues or incorrect HTML structure.

Solution:

1. Check your theme’s CSS for proper float or flex properties on content and sidebar containers.
2. Ensure your HTML structure is correct, with sidebar and content in appropriate wrapper divs.
3. Use browser developer tools to inspect the layout and identify CSS issues.
4. If using a responsive theme, check media queries to ensure proper behavior on different screen sizes.

5. Missing Style.css Error

WordPress requires a style.css file in the root of your theme directory. If it’s missing or improperly formatted, you’ll see an error.

Cause: Deleted or renamed style.css file, or incorrect theme header in the file.

Solution:

1. Ensure style.css exists in your theme’s root directory.
2. Check that the theme header in style.css is properly formatted:

   /*
   Theme Name: Your Theme Name
   Theme URI: http://example.com/
   Author: Your Name
   Author URI: http://example.com/
   Description: Your theme description
   Version: 1.0
   License: GNU General Public License v2 or later
   License URI: http://www.gnu.org/licenses/gpl-2.0.html
   Text Domain: your-theme-textdomain
   */
   

3. If using a child theme, ensure it’s properly set up with its own style.css file.

Conclusion

These five common WordPress theme errors can be frustrating, but with the right approach, they’re solvable. Remember to always back up your site before making changes, use a child theme for customizations, and keep your themes and plugins updated.

By understanding these errors and their solutions, you’ll be better equipped to maintain and troubleshoot WordPress themes effectively.