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MPG Troubleshooting Guide ​

This guide contains common queries that may help you work with MPG. For more information about the MPG plugin, please refer to the main documentation.

General requirements ​

  • Make sure you are using the latest version of the plugin.
  • If you are using a direct link to the source file, make sure that you share your Google Sheet before using that link. Sometimes, unwanted characters at the end of the link cause an error message stating “Datatable is not defined.”
  • Make sure the headers in the source file do not contain any brackets like {{title}}, {{mpg_title}}, [[title]]. Also, there is no need to include the prefix “mpg” in front of the header, as it is automatically added by our plugin. Avoid using header names that contain spaces or the underscore “_” character.
  • When replacing or migrating a data source (for example, switching from an Excel file to a Google Sheets link), make sure the new source has the same column headers, column count, and column order as the original. A mismatch between the old and new column structure is the most common cause of “DataTables warning: Requested unknown parameter” errors. After replacing the source, click Fetch and use to reload the data into your project.

Common issues and solutions ​

A project cannot be saved / URLs disappear from the project ​

Please navigate to the Advanced Settings page within the MPG plugin settings and click the Update Table Structure button, as shown in this screenshot:

MPG Update Table Structure

Where can I find the generated pages? ​

MPG-generated pages are virtual pages, not directly accessible on your Dashboard/editor, so you won't find them under the pages section like normal pages or posts. You can access them through the URLs generated in the MPG Project. More details can be found here.

Update the content of existing pages ​

To update existing pages, make changes in your source file and click the Fetch and use button in the Project settings.

If Fetch and use does not update the frontend ​

If your generated URLs still show old template blocks or shortcode output after using Fetch and use, follow our dedicated guide: Generated Pages Show Outdated Content After Updates.

Check these common causes first:

  1. Test the Page Builders Compatibility setting in Multiple Pages Generator > Advanced Settings.
  2. Purge all cache layers (plugin, server/hosting, CDN, and browser cache), then retest in an incognito/private window.
  3. Confirm your source file does not use url as a column header, because url is reserved by MPG.
  4. Review your source values and template content for invalid or unclosed HTML, which can break frontend rendering and make updates appear stale.

Fatal error: Cannot use output buffering in output buffering display handlers ​

If you see preg_replace(): Cannot use output buffering in output buffering display handlers in your PHP error log (often pointing to MPG Helper.php), your theme or page builder is likely using output buffering in a way that conflicts with MPG search/query-loop injection.

To isolate the conflict:

  1. Open MPG > All Projects and edit the affected project.
  2. Disable Include generated pages in your site search results.
  3. Disable Display generated pages in your site content listings and query loop.
  4. Save the project.
  5. Clear all cache layers (plugin, server/hosting, CDN, and browser cache).
  6. Retest the affected generated URLs and your site search.
If you still need MPG pages in search or query loops ​

If your site needs one or both options above, re-enable them one at a time and test after each change. Also test with different Page Builders Compatibility values if your theme/page builder supports multiple rendering modes.

If the fatal error returns, keep the conflicting option disabled and collect your PHP error logs before contacting support so the team can confirm the exact conflict on your setup.

How to get the source files of the pre-built projects ​

  • Create the project first, then open it.
  • Go to the source accordion and click the Download button next to the file to download a CSV file. 📝 Note: If the download button doesn’t work, access the source file from the "mpg-uploads" folder within the wp-content folder of your WordPress installation.

Please refer to our dedicated guide.

Use Rankmath/Yoast SEO with MPG ​

You can use an SEO plugin like Rankmath or Yoast SEO with MPG. To generate meta titles and descriptions for MPG pages, edit your template page and add MPG shortcodes like {{mpg_COLUMN-NAME}} under the meta title and description fields, as shown in this screenshot:

Rankmath SEO with MPG

While using SEO plugins, make sure the template page is not marked as "no index" to prevent all generated pages from being indexed.

DataTables warnings on data import/migration ​

If you see a browser warning similar to “DataTables warning: Requested unknown parameter ‘X’ for row N, column N” after importing or migrating your data source, this means the column headers in the new source file do not match what MPG has cached from the previous source.

Common causes:

  • Switching from one file type to another (for example, Excel to Google Sheets) without keeping the same column names and order.
  • Renaming, adding, or removing columns in the source file without refreshing the project.
  • Extra whitespace or special characters in header names that make them appear identical but differ internally.

How to fix it:

  1. Open your data source (Google Sheet or Excel file) and compare the column headers to those listed in the MPG project settings.
  2. Make sure the column names, column count, and column order in the new source exactly match the original.
  3. Correct any mismatched or renamed headers in the source file.
  4. In the MPG project settings, click Fetch and use to reload the updated data.
  5. After fetching, preview one of the generated pages to confirm the warning is gone.

Generated pages give a 404 error ​

We have a dedicated guide to debug this issue, which you can find here.

Caching plugin conflicts ​

Caching plugins sometimes purge or delete files from the wp-content/mpg-uploads/ directory. These files contain index data that MPG needs to serve generated pages. When caching removes them, pages that were previously working may start returning 404 errors.

📝 Since recent MPG updates: Projects that use Upload file as the source type can automatically rebuild missing index data from the original uploaded source file when a generated URL is requested. This recovery works only if the original uploaded CSV, XLSX, or ODS file is still available on your server.

Symptoms:

  • MPG pages return 404 errors after a caching operation (full-site purge, scheduled cleanup, or plugin update).
  • The errors disappear temporarily when the MPG project is saved or re-fetched, then return after the next cache purge.
  • 404 errors affect multiple projects at once rather than individual pages.

How to fix it:

  1. Visit one affected generated URL once to let MPG attempt automatic index recovery.
  2. If the URL still returns 404, open the affected project and confirm the uploaded source file is still available. Re-upload the file and click Fetch and use if needed.
  3. Open your caching plugin settings (for example, WP Rocket, W3 Total Cache, LiteSpeed Cache, or WP Super Cache). Note that the exact menu location and option names vary between plugins — consult your caching plugin's documentation if you are unsure where to find these settings.
  4. Find the file or directory exclusion settings for cache purge or cleanup rules.
  5. Add wp-content/mpg-uploads/ to the exclusion list so the caching plugin does not delete files in that folder again.
  6. Save the settings and perform a manual cache purge.
  7. Visit one of the affected MPG pages to confirm it loads correctly.

⚠️ Important: The exact location of the exclusion setting varies by caching plugin. Look for options labeled Never cache the following pages, Excluded files, or Purge exclusions. Consult your caching plugin's documentation if you cannot locate this setting.

Project data missing after site migration ​

If MPG shows an error like could not open ... wp-content/mpg-uploads/...csv for reading! file does not exist after moving or restoring your site, the source files for one or more projects were not transferred.

MPG stores uploaded CSV, XLSX, and ODS source files in wp-content/mpg-uploads/. Some migration tools copy the database, themes, plugins, and media uploads but skip custom folders directly under wp-content/, which can leave MPG projects without their source files.

How to recover project data:

  1. Copy wp-content/mpg-uploads/ from the old host to the same path on the new host.
  2. If the old host is unavailable, restore wp-content/mpg-uploads/ from a full-site backup.
  3. If you do not have a backup, ask your previous host for a server snapshot that includes wp-content/mpg-uploads/.
  4. If recovery is not possible, re-upload the original source file in each affected MPG project and click Fetch and use.
Before migrating an MPG site ​
  1. Verify your migration or backup tool includes the full wp-content/mpg-uploads/ directory.
  2. If your migration plugin has a custom include/exclude list, explicitly include wp-content/mpg-uploads/.
  3. Keep a separate backup copy of wp-content/mpg-uploads/ before you start the migration.
After migration ​
  1. Confirm wp-content/mpg-uploads/ exists on the new server and contains your project source files.
  2. Open each MPG project and make sure the source file is still attached.
  3. Click Fetch and use to refresh project data after the move.
  4. Test a few generated URLs to confirm they load correctly.

Generated pages have missing or broken styles when using Divi ​

If MPG-generated pages show incorrect fonts or colors, a broken hero section, or layout differences between logged-in and logged-out visitors, Divi's CSS optimization settings may be stripping required styles from the virtual pages.

Symptoms:

  • The template looks correct in the Divi editor, but generated URLs render with different fonts, colors, or hero section styling.
  • Styling appears correct when logged in but breaks for logged-out visitors.

How to fix it:

  1. In Divi's performance settings, locate the CSS optimization options and disable Static CSS File Generation, Dynamic CSS File Generation, and Critical CSS Generation. Test disabling them one at a time to identify which setting is causing the conflict.
  2. After each change, clear Divi's cached CSS files using the built-in clear or purge option in Divi's performance settings.
  3. Clear all other cache layers: your caching plugin, server or hosting cache, and any CDN cache.
  4. Open a generated MPG URL in an incognito or private browsing window to confirm the styling is restored.

Generated URLs redirect to the homepage ​

  • Ensure no redirection plugins are active in your dashboard.
  • Check that generated URLs don’t contain special characters.
  • If using page builder plugins, try the page builder compatibility options available under MPG > Advanced settings. Refer to this screenshot:

MPG Page Builder Compatibility

Sitemap not generated ​

We have a dedicated guide for creating a sitemap that you can check here. If issues persist, check the WordPress base path settings under MPG Advanced Settings. See this screenshot for reference:

MPG WordPress Base Path Settings

MPG pages not indexed ​

It's important to understand that search engines manage the indexing process, which involves various factors beyond the direct control of our plugin. While our plugin facilitates the creation of SEO-friendly pages and sitemaps, the final indexing relies on search engines like Google.

📝 Note: If you still need help, feel free to contact our support team - pro users/free users.