Title: Critical Error While Using Stackable – Page Builder Gutenberg Blocks
Last modified: September 30, 2025

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# Critical Error While Using Stackable – Page Builder Gutenberg Blocks

 *  [Kausar Al Mamun](https://wordpress.org/support/users/kamplugins/)
 * (@kamplugins)
 * [7 months, 4 weeks ago](https://wordpress.org/support/topic/critical-error-while-using-stackable-page-builder-gutenberg-blocks/)
 * Hello Stackable Support Team,
 * I am experiencing a **critical error** on my WordPress site when I activate and
   use the **Stackable – Page Builder Gutenberg Blocks** plugin.
 * Here is the error log:
 * `PHP Fatal error: Uncaught TypeError: strpos(): Argument #1 ($haystack) must 
   be of type string, array given in /public_html/wp-content/plugins/stackable-ultimate-
   gutenberg-blocks-premium/src/init.php:529`
   `Stack trace: #0 /public_html/wp-content/
   plugins/stackable-ultimate-gutenberg-blocks-premium/src/init.php(529): strpos()#
   1 /public_html/wp-content/plugins/stackable-ultimate-gutenberg-blocks-premium/
   src/init.php(556): stackable_css_has_hover_effects_or_animation() #2 /public_html/
   wp-includes/class-wp-hook.php(324): stackable_check_block_animation_on_global_styles()#
   3 /public_html/wp-includes/plugin.php(205): WP_Hook->apply_filters() #4 /public_html/
   wp-content/plugins/stackable-ultimate-gutenberg-blocks-premium/src/css-optimize.
   php(237): apply_filters() #5 /public_html/wp-includes/class-wp-hook.php(324):
   Stackable_CSS_Optimize->print_optimized_styles() #6 /public_html/wp-includes/
   class-wp-hook.php(348): WP_Hook->apply_filters() #7 /public_html/wp-includes/
   plugin.php(517): WP_Hook->do_action() #8 /public_html/wp-includes/general-template.
   php(3192): do_action() #9 /public_html/wp-includes/template-canvas.php(17): wp_head()#
   10 /public_html/wp-includes/template-loader.php(106): include('/home/u76854374…')#
   11 /public_html/wp-blog-header.php(19): require_once('/home/u76854374…') #12 /
   public_html/index.php(17): require('/home/u76854374…') #13 {main}
 * `thrown in /public_html/wp-content/plugins/stackable-ultimate-gutenberg-blocks-
   premium/src/init.php on line 529`
 * This issue is not limited to just one file — I have noticed it appearing in multiple
   places where similar functions are used.
 * Could you please help me resolve this issue or provide a fix/workaround?
 * Thank you in advance for your support.
 * Best regards,
    -  This topic was modified 7 months, 4 weeks ago by [Kausar Al Mamun](https://wordpress.org/support/users/kamplugins/).

Viewing 1 replies (of 1 total)

 *  [Charmela Malala](https://wordpress.org/support/users/charmela/)
 * (@charmela)
 * [7 months, 3 weeks ago](https://wordpress.org/support/topic/critical-error-while-using-stackable-page-builder-gutenberg-blocks/#post-18665088)
 * Hi [@kamplugins](https://wordpress.org/support/users/kamplugins/) ,
 * Thanks for reaching out!
 * Could you send over some login details to our support email **support@wpstackable.
   com** so we can check this further? We would also need FTP access. Sending these
   details will also allow us to create a ticket on your behalf and properly track
   the issue.
 * Thank you!
    -  This reply was modified 7 months, 3 weeks ago by [Charmela Malala](https://wordpress.org/support/users/charmela/).

Viewing 1 replies (of 1 total)

The topic ‘Critical Error While Using Stackable – Page Builder Gutenberg Blocks’
is closed to new replies.

 * ![](https://ps.w.org/stackable-ultimate-gutenberg-blocks/assets/icon-256x256.
   png?rev=2749547)
 * [Stackable - Page Builder Gutenberg Blocks](https://wordpress.org/plugins/stackable-ultimate-gutenberg-blocks/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/stackable-ultimate-gutenberg-blocks/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/stackable-ultimate-gutenberg-blocks/)
 * [Active Topics](https://wordpress.org/support/plugin/stackable-ultimate-gutenberg-blocks/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/stackable-ultimate-gutenberg-blocks/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/stackable-ultimate-gutenberg-blocks/reviews/)

 * 1 reply
 * 2 participants
 * Last reply from: [Charmela Malala](https://wordpress.org/support/users/charmela/)
 * Last activity: [7 months, 3 weeks ago](https://wordpress.org/support/topic/critical-error-while-using-stackable-page-builder-gutenberg-blocks/#post-18665088)
 * Status: not resolved