# Critical Error: Call to undefined function mb\_convert\_encoding

**URL:** <https://meta.discourse.org/t/critical-error-call-to-undefined-function-mb-convert-encoding/386125>\
**Category:** WordPress\
**Created:** [October 19, 2025, 7:04pm UTC](https://meta.discourse.org/t/critical-error-call-to-undefined-function-mb-convert-encoding/386125 "2025-10-19T19:04:44Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![angus](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/angus/32/341715_2.png) [@angus](https://meta.discourse.org/u/angus)\
**Post date:** [October 20, 2025, 9:43am UTC](https://meta.discourse.org/t/critical-error-call-to-undefined-function-mb-convert-encoding/386125/2 "2025-10-20T09:43:50Z")

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Hey Alan, you need php’s [mbstring](https://www.php.net/manual/en/book.mbstring.php) installed and enabled to run [WP Discourse](https://github.com/discourse/wp-discourse). Please ask your Wordpress site admin to install and / or enable it.

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_[View the full topic](https://meta.discourse.org/t/critical-error-call-to-undefined-function-mb-convert-encoding/386125)._