---
title: "Troubleshooting \"Warning: igbinary_unserialize_...\" warnings with the Memcache module"
date: "2022-02-23T23:24:04+00:00"
summary:
image:
type: "article"
url: "/acquia-cloud-platform/help/94576-troubleshooting-warning-igbinaryunserialize-warnings-memcache-module"
id: "5c601af9-af0d-4ff2-bf38-38afd10cc302"
---

Table of contents will be added

Issue
-----

Your Drupal site is triggering warnings that mention **igbinary**, similar to (but not limited to) the following:

    Warning: igbinary_unserialize_header: unsupported version: [NUMBER], should be [...]

    Warning: igbinary_unserialize_header: unsupported version: "[STRING]"..., should begin with [...]

    Warning: igbinary_unserialize_zval: unknown type [...]

    Warning: igbinary_unserialize_chararray: end-of-data in [...]

Resolution
----------

Add this configuration in the Memcache section of your site's settings.php file:

      // Force memcache to use PHP's core serialize functions
      $conf['memcache_serialize'] = 'serialize';

Cause
-----

Later versions of the Memcache module default to using the **igbinary** serializer, however, within Acquia Cloud the best practice is to use the PHP native serializer.