Title: Fatal Error at Activation
Last modified: January 2, 2023

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# Fatal Error at Activation

 *  [jason_hayes](https://wordpress.org/support/users/jason_hayes/)
 * (@jason_hayes)
 * [3 years, 3 months ago](https://wordpress.org/support/topic/fatal-error-at-activation-12/)
 * I’m getting a fatal error when activating the plugin. Here’s the error:
 * **Fatal error**: Cannot redeclare wp_cache_add() (previously declared in /public_html/
   wp-includes/cache.php:41) in **/public_html/wp-content/plugins/memcached/object-
   cache.php** on line **19**

Viewing 4 replies - 1 through 4 (of 4 total)

 *  [Wiliam Jose Koester](https://wordpress.org/support/users/wiliamjk/)
 * (@wiliamjk)
 * [3 years, 3 months ago](https://wordpress.org/support/topic/fatal-error-at-activation-12/#post-16359962)
 * Same!
 * Answer here: [https://wordpress.org/support/topic/cannot-redeclare-wp_cache/](https://wordpress.org/support/topic/cannot-redeclare-wp_cache/)
    -  This reply was modified 3 years, 3 months ago by [Wiliam Jose Koester](https://wordpress.org/support/users/wiliamjk/).
    -  This reply was modified 3 years, 3 months ago by [Wiliam Jose Koester](https://wordpress.org/support/users/wiliamjk/).
 *  [mcgoofy](https://wordpress.org/support/users/mcgoofy/)
 * (@mcgoofy)
 * [3 years, 3 months ago](https://wordpress.org/support/topic/fatal-error-at-activation-12/#post-16373494)
 * Same Problem! Fatal Error at the installation.
 * n.b. this plugin installation is absolutely user-unfriendly. Installations that
   start with an error?! bad setup, very complicated and poorly explained. That 
   must have been done better.
 * MrNight
 *  Plugin Contributor [Andrija Vučinić](https://wordpress.org/support/users/aidvu/)
 * (@aidvu)
 * [3 years, 3 months ago](https://wordpress.org/support/topic/fatal-error-at-activation-12/#post-16376553)
 * Hi [@mcgoofy](https://wordpress.org/support/users/mcgoofy/), suggestions are 
   welcome.
 *  [Madalin Ignisca](https://wordpress.org/support/users/madalin-ignisca/)
 * (@madalin-ignisca)
 * [3 years, 1 month ago](https://wordpress.org/support/topic/fatal-error-at-activation-12/#post-16498707)
 * To make the plugin user friendly it should support normal activation.
 * On activation, should test if it can write to wp-content folder and if memcached
   extension is available (test any of memcached functions/classes exist).
 * Ideally, if it can write, it should ask the user to accept the caching php script
   to be copied to the correct location.
 * A hook for uninstall/delete could be to also delete the cache script (testing
   if could do it for alerting the user if not).
 * With the idea of the user to do manual steps, makes the plugin available only
   for developers and more technical people.

Viewing 4 replies - 1 through 4 (of 4 total)

The topic ‘Fatal Error at Activation’ is closed to new replies.

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## Tags

 * [complicated](https://wordpress.org/support/topic-tag/complicated/)
 * [fatal error](https://wordpress.org/support/topic-tag/fatal-error/)

 * 4 replies
 * 5 participants
 * Last reply from: [Madalin Ignisca](https://wordpress.org/support/users/madalin-ignisca/)
 * Last activity: [3 years, 1 month ago](https://wordpress.org/support/topic/fatal-error-at-activation-12/#post-16498707)
 * Status: not resolved