Having trouble with call to undefined error with Duplicator Pro? This guide provides practical solutions to troubleshoot and resolve this issue effectively.

To begin with, make sure you are using the latest version of Duplicator Pro. Please check the changelog and system requirements.

Problem Overview

If you encounter an error message stating “Uncaught Error: Call to undefined function” while using the Duplicator plugin, your hosting environment may be running an uncommon or misconfigured version of PHP. Below are the recommended solutions to resolve this issue.

Common Error Messages

• Uncaught Error: Call to undefined function
• ERR_EMPTY_RESPONSE

Possible Solutions

Solution 1: Contact Your Hosting Provider

In most cases, this error can be resolved by contacting your hosting provider. Simply forward the error message to them for assistance. For example, if your log contains the following error:

INSTALLER ERROR:[PHP ERR][FATAL] MSG:Uncaught Error: Call to undefined function token_get_all() in /var/www/localhost/htdocs/wordpress/duplicator/dup-installer/lib/config/class.wp.config.tranformer.php:387

Note: Send this error message to your host or server administrator. They will typically be able to enable the necessary function.

Solution 2: Plugin and Theme Updates

When migrating to a new hosting environment, hosts may apply custom configurations that restrict certain PHP functions. If you receive an “undefined function” message, try the following steps:

1. Deactivate All Plugins – Disable all installed plugins and attempt to replicate the issue.
2. Switch Themes – Temporarily switch to a default WordPress theme (such as Twenty Twenty-Five) to rule out theme-related conflicts.

Note:If the error disappears after these steps, reactivate each plugin one by one to identify the conflicting plugin.

Solution 3: Perform a Manual Update

If you prefer to troubleshoot the issue manually, check the following:

1. Ensure PHP is Updated: WordPress recommends running PHP 7.4 or later. If you’re using an outdated version, upgrading may resolve the issue.
2. Check php.ini Settings: Verify if disable_functions = in your php.ini file is preventing certain PHP functions from running.

Related Fixes for Post/Page Updates

Some users may experience an “undefined function” error due to host-imposed line length limitations. If this occurs, adding the following code to your .htaccess file may help:

# BEGIN Line too long fix
<IfModule mod_substitute.c>
    SubstituteMaxLineLength 10M
</IfModule>
# END Line too long fix

Additional Resources

For further troubleshooting, refer to these external resources:

• Dev Answers: Fixing Uncaught Error: Call to Undefined Function
• Stack Overflow: IMAP Enabled but Functions Undefined