BugWP logo BugWP
Back to Community
Home / Community / Core → Networking wordpress

Troubleshooting Common WordPress Multisite Theme and Menu Editor Issues

41 threads Sep 7, 2025 Core → Networking wordpress

Content

WordPress Multisite is a powerful tool for managing multiple websites from a single installation. However, its network-based nature can introduce unique challenges, particularly with theme functionality and the menu editor in subsites. Based on community reports, this guide outlines the most common problems and their solutions.

Common Multisite Theme Issues

1. Parent Theme Missing Error

The Problem: After uploading a child theme to a Multisite network, you receive an error stating "The parent theme is missing," even though the parent theme is installed and active. This can cause incorrect fonts, broken styling, and even white screens when trying to edit the child theme.

Why It Happens: This is often a path resolution issue within the Multisite environment. The system may have trouble correctly identifying the location of the parent theme's files.

Potential Solutions:

  • Re-upload the Parent Theme: Network deactivate and delete the parent theme. Then, reinstall and network activate it again. This can refresh the file paths the system uses.
  • Check File Permissions: Ensure the parent theme's directory on the server has the correct read and execute permissions.
  • Review the Child Theme Header: Double-check the child theme's style.css file. The Template: line must exactly match the directory name of the parent theme.

2. Inability to Change the Main Site Theme

The Problem: You try to switch the theme on your network's main site. The admin panel shows the new theme as active, but the front-end of the site continues to display the old theme.

Why It Happens: Object Caching (e.g., Memcached, Redis) or persistent caching plugins can serve outdated content. Domain mapping configurations can also sometimes interfere with theme loading.

Potential Solutions:

  • Clear All Caches: Purge your server-level cache, any object cache, and your WordPress caching plugin's cache.
  • Check for Conflicts: Temporarily network deactivate all plugins to see if the issue resolves. If it does, reactivate them one by one to identify the culprit.

3. Site & Theme Editors Not Loading (White Screen)

The Problem: Clicking on Appearance → Theme Editor or the Site Editor (for block themes) results in a blank white screen or a non-functional page.

Why It Happens: This is frequently caused by a security feature in WordPress core that intentionally disables the theme file editor on Multisite installations due to potential security risks. It can also be caused by a plugin or theme conflict.

Potential Solutions:

  • Do NOT Modify Core Files: While editing wp-admin/includes/file.php can make the editor work, this is a temporary and dangerous fix. Your changes will be overwritten with the next WordPress update, potentially breaking your site.
  • Use SFTP/File Manager: The recommended and safest way to edit theme files is directly through your web host's file manager or an SFTP client.
  • Conflict Test: A white screen can indicate a PHP error. Enable WP_DEBUG to reveal any hidden errors that point to the problematic plugin or theme.

Common Multisite Menu Editor Issues

1. Menu Editor Tabs Not Expanding in Subsites

The Problem: In a subsite's menu editor (Appearance → Menus), you can only add Pages. The tabs for Posts, Custom Links, and Categories are collapsed and will not expand when clicked, making it impossible to add those items to a menu.

Why It Happens: This is almost always a JavaScript conflict. A plugin or theme is loading a script on the subsite's admin page that is interfering with the default WordPress scripts responsible for the menu editor's functionality.

Potential Solutions:

  • Standard Conflict Test: This is the most effective first step.
    1. On the problematic subsite, switch its theme to a default WordPress theme (e.g., Twenty Twenty-Four).
    2. Network deactivate all plugins.
    3. Check if the menu editor works. If it does, network reactivate plugins one by one, checking the menu editor after each, to identify the conflicting plugin.
  • Browser Console Check: Open your browser's developer tools (F12) and check the "Console" tab for any JavaScript errors when the page loads or when you click the tabs. These errors can pinpoint the source of the conflict.

2. Screen Options Not Working

The Problem: The checkboxes in the Screen Options tab on subsite dashboards have no effect, preventing you from showing or hiding dashboard widgets.

Why It Happens: Similar to the menu editor issue, this is typically a JavaScript conflict, often caused by a poorly coded theme or plugin that is not fully compatible with Multisite.

Potential Solutions:

  • Follow the same Conflict Test procedure outlined above. The issue has been specifically linked to certain themes in community reports.

General Multisite Troubleshooting Tips

  • Always Test for Conflicts: The vast majority of strange behavior in Multisite stems from plugin or theme conflicts. Learn the standard deactivation and reactivation process.
  • Enable Debugging: Always turn on WP_DEBUG when investigating an issue. It will reveal errors that are hidden by default.
  • User Roles Matter: Remember that in Multisite, regular administrators of individual subsites do not have the same capabilities as the Network Super Admin. Some settings, like the option to store uploads in year/month folders, are only accessible to the Super Admin in the network settings.

If you continue to experience issues, describing your specific problem in detail on support forums like WordPress.org can help the community provide more targeted assistance.

Related Support Threads Support