Title: Free version: Undefined variable error references pro-only variable
Last modified: September 19, 2025

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# Free version: Undefined variable error references pro-only variable

 *  Resolved [Geren](https://wordpress.org/support/users/geren/)
 * (@geren)
 * [8 months, 3 weeks ago](https://wordpress.org/support/topic/free-version-undefined-variable-error-references-pro-only-variable/)
 * I’ve just noticed that when using the free version of the Publish Press Series
   plugin, I’m seeing the following error on my series posts:
   **Warning**: Undefined
   variable $maximum_items in **/home/gerenm/www/www/wp-content/plugins/organize-
   series/addons/post-list-box/classes/PostListBoxRenderer.php** on line **54**After
   digging around looking for a place to define the max number of items, I’m finding
   that it’s a pro-only feature. Since I hadn’t noticed this before, I’m assuming
   that it started after the update to version 2.15.0. Thanks!
 * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Ffree-version-undefined-variable-error-references-pro-only-variable%2F%3Foutput_format%3Dmd&locale=en_US)
   to see the link]_

Viewing 5 replies - 1 through 5 (of 5 total)

 *  Plugin Support [Riza Prihananto](https://wordpress.org/support/users/rizaprihananto/)
 * (@rizaprihananto)
 * [8 months, 3 weeks ago](https://wordpress.org/support/topic/free-version-undefined-variable-error-references-pro-only-variable/#post-18650699)
 * Hi [@geren](https://wordpress.org/support/users/geren/) , 
   Thank you for using
   our plugin. Could you try to download this version and install it to replace 
   the existing one? [https://drive.google.com/file/d/1ojLWRqteCD4dsrhOOYku0iWryhEkE9rn/view?usp=sharing](https://drive.google.com/file/d/1ojLWRqteCD4dsrhOOYku0iWryhEkE9rn/view?usp=sharing)
   Then, disable the wp_debug to check the error. Let me know how it goes
 *  Thread Starter [Geren](https://wordpress.org/support/users/geren/)
 * (@geren)
 * [8 months, 3 weeks ago](https://wordpress.org/support/topic/free-version-undefined-variable-error-references-pro-only-variable/#post-18651410)
 * Thanks! One possibly dumb question — where am I disabling wp_debug? It’s not 
   present in my wp-config file, and adding the line “define(‘WP_DEBUG’, false);”
   causes a warning that WP_DEBUG being previously defined to appear. (as on this
   page: [https://gerenm.net/korgs-ive-owned-part-1-ds-8-and-sqd-8/](https://gerenm.net/korgs-ive-owned-part-1-ds-8-and-sqd-8/)).
   I admit that I’ve gotten lazy — it’s been a very long time since I’ve dug around
   under the hood in WordPress or in plug-ins, except to modify some CSS here and
   there.
 * Thanks again!
 *  Thread Starter [Geren](https://wordpress.org/support/users/geren/)
 * (@geren)
 * [8 months, 3 weeks ago](https://wordpress.org/support/topic/free-version-undefined-variable-error-references-pro-only-variable/#post-18651868)
 * I was able to get WP_DEBUG turned off. However, I’m still seeing the original
   error after installing the provided version of Publish Press Series.
 * Thanks.
 *  Thread Starter [Geren](https://wordpress.org/support/users/geren/)
 * (@geren)
 * [8 months, 2 weeks ago](https://wordpress.org/support/topic/free-version-undefined-variable-error-references-pro-only-variable/#post-18652287)
 * And FYI … For the moment, I’ve commented out line 54 in PostListBoxRenderer.php.
   I’m not sure what else (if anything) that might break, but it’s made the error
   go away. Nothing appears to have died.
 *  Plugin Author [Riza Maulana Ardiyanto](https://wordpress.org/support/users/rizaardiyanto/)
 * (@rizaardiyanto)
 * [8 months, 1 week ago](https://wordpress.org/support/topic/free-version-undefined-variable-error-references-pro-only-variable/#post-18665028)
 * Thanks guys for letting us know. I have a fix already for this and it will be
   included in the next release.

Viewing 5 replies - 1 through 5 (of 5 total)

The topic ‘Free version: Undefined variable error references pro-only variable’ 
is closed to new replies.

 * ![](https://ps.w.org/organize-series/assets/icon-256x256.png?rev=3386599)
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 * 5 replies
 * 3 participants
 * Last reply from: [Riza Maulana Ardiyanto](https://wordpress.org/support/users/rizaardiyanto/)
 * Last activity: [8 months, 1 week ago](https://wordpress.org/support/topic/free-version-undefined-variable-error-references-pro-only-variable/#post-18665028)
 * Status: resolved