Title: Error: Call to undefined function is_plugin_active()
Last modified: March 3, 2022

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# Error: Call to undefined function is_plugin_active()

 *  [deltafactory](https://wordpress.org/support/users/deltafactory/)
 * (@deltafactory)
 * [4 years, 3 months ago](https://wordpress.org/support/topic/error-call-to-undefined-function-is_plugin_active/)
 * The plugin calls `is_plugin_active()` when the plugin is loaded. Elsewhere I’ve
   read that this will cause a crash if called before the `admin_init` hook, or 
   if the file is manually included.
 * Not entirely sure why this isn’t more widespread of a problem. I assume another
   plugin earlier in the page lifecycle may load the library with the function defined.
 * WordPress 5.9.1
    Events Manager 5.12.1 Events Manager Pro 2.6.7.2 Events Manager–
   Move Bookings 2.0.2

The topic ‘Error: Call to undefined function is_plugin_active()’ is closed to new
replies.

 * ![](https://ps.w.org/stonehenge-em-move-bookings/assets/icon-256x256.png?rev=
   2662670)
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 * 0 replies
 * 1 participant
 * Last reply from: [deltafactory](https://wordpress.org/support/users/deltafactory/)
 * Last activity: [4 years, 3 months ago](https://wordpress.org/support/topic/error-call-to-undefined-function-is_plugin_active/)
 * Status: not resolved