Title: Error: gmp missing
Last modified: November 21, 2021

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# Error: gmp missing

 *  Resolved [richards1052](https://wordpress.org/support/users/richards1052/)
 * (@richards1052)
 * [4 years, 6 months ago](https://wordpress.org/support/topic/error-gmp-missing/)
 * When trying to install and activate the plugin I got this error:
 * > PHP extension gmp doesn’t seem to exist, rendering WP-WebAuthn unable to function.
 * What does this mean and how can I fix it?
 * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Ferror-gmp-missing%2F%3Foutput_format%3Dmd&locale=en_US)
   to see the link]_

Viewing 1 replies (of 1 total)

 *  Plugin Author [Axton](https://wordpress.org/support/users/axton/)
 * (@axton)
 * [4 years, 6 months ago](https://wordpress.org/support/topic/error-gmp-missing/#post-15088842)
 * Hi,
 * PHP gmp is a PHP extension. WP-WebAuthn uses this extension to handle with big
   integers so you need to install it for your PHP to use WP-WebAuthn.
 * The way to install the extension may be various and depending on the platform.
   For example, if you are using a PHP management panel you may able to find a section
   to install it with one click, or you may need to run some install commands if
   you manage the PHP instance by yourself. Since the extension is widely used, 
   you can find some help by simply searching it.
 * Hope this can help. I’d like to help if you offer more information.

Viewing 1 replies (of 1 total)

The topic ‘Error: gmp missing’ is closed to new replies.

 * ![](https://ps.w.org/wp-webauthn/assets/icon-256x256.png?rev=2468754)
 * [WP-WebAuthn](https://wordpress.org/plugins/wp-webauthn/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/wp-webauthn/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/wp-webauthn/)
 * [Active Topics](https://wordpress.org/support/plugin/wp-webauthn/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/wp-webauthn/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/wp-webauthn/reviews/)

## Tags

 * [php](https://wordpress.org/support/topic-tag/php/)

 * 1 reply
 * 2 participants
 * Last reply from: [Axton](https://wordpress.org/support/users/axton/)
 * Last activity: [4 years, 6 months ago](https://wordpress.org/support/topic/error-gmp-missing/#post-15088842)
 * Status: resolved