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Fixing the 'Checking extensions compatibility...' Stuck Import in All-in-One WP Migration

36 threads Sep 7, 2025 Plugin → All-in-one wp migration and backup

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Why Your All-in-One WP Migration Import Gets Stuck

A common and frustrating issue users encounter with the All-in-One WP Migration plugin is the import process freezing at the "Checking extensions compatibility..." stage. Based on community reports and troubleshooting threads, this problem can stem from several underlying causes, most commonly related to server configuration, file permissions, or a specific bug within the plugin.

Common Causes and Their Solutions

1. The "Division by Zero" Bug

Several user reports, including recent ones from late 2024, point to a specific PHP error causing this hang-up:

PHP Fatal error: Uncaught DivisionByZeroError: Division by zero in .../all-in-one-wp-migration/lib/model/import/class-ai1wm-import-validate.php

This error appears to be a bug within the plugin's validation logic. When the plugin cannot determine the size of the uploaded .wpress file (see the related filesize(): stat failed error), a calculation divides by zero, crashing the process.

What to do: This is an issue that likely requires a patch from the plugin developers. Keep your plugin updated to the latest version, as the 'All-in-One WP Migration and Backup' team may have addressed it in a recent release.

2. Server Configuration and Upload Limits

Even if the export worked perfectly, the import process can fail due to server constraints on the destination server.

  • HTTP 413 Error: This error in your browser's console (POST ... 413) means the request entity is too large. Your server (often NGINX) or hosting provider has a limit on the size of a request.
  • PHP Memory and Execution Time: The compatibility check involves scanning files, which can timeout on slower servers or sites with many files.

What to do:

  • Contact your hosting provider and ask them to increase the client_max_body_size (for NGINX) and the post_max_size & upload_max_filesize (in PHP settings) to be larger than your backup file.
  • Try increasing the max_execution_time and memory_limit in your php.ini file.

3. File Permissions and Missing Files

The error filesize(): stat failed for /path/to/file.wpress indicates the plugin cannot find or read the archive it just uploaded.

What to do:

  • Check the permissions of the wp-content/plugins/all-in-one-wp-migration/storage/ directory. The web server (e.g., www-data) needs write permissions to this folder to save and read the uploaded file.
  • Ensure there is enough disk space on the server for the extraction process.

4. Plugin or Theme Conflicts

While the check is for "extensions" (the plugin's add-ons), conflicts with other plugins or themes can sometimes cause unexpected behavior.

What to do:

  • As a test, try creating a fresh WordPress installation on the same server and only install the All-in-One WP Migration plugin. Attempt the import. If it works, a conflict on your main site is likely.
  • Enable WP_DEBUG before importing. Open a new browser tab and load your site's homepage. Any fatal errors that appear could reveal the conflicting plugin or theme.

Summary of Troubleshooting Steps

  1. Update Everything: Ensure the All-in-One WP Migration plugin is updated to the latest version.
  2. Check Server Logs: Look in your server's error log and the wp-content/plugins/all-in-one-wp-migration/storage/error.log file for specific PHP errors.
  3. Verify Server Limits: Confirm your PHP and web server configurations allow for large file uploads and long execution times.
  4. Check File Permissions: Ensure the plugin's /storage/ directory is writable.
  5. Test for Conflicts: Use a default theme (like Twenty Twenty-Four) and disable all other plugins as a test.

By methodically working through these potential causes, you can identify and resolve the issue that is halting your website migration.

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