Critical Fatal Error – Infinite Recursion in WPML (Confirmed Not Server-Side Issue)

This thread is resolved. Here is a description of the problem and solution.

Problem:
You are experiencing a critical fatal error indicating 'Maximum call stack size' exceeded due to infinite recursion within the WPML plugin. This issue causes site instability and is not related to server or PHP configuration but rather a potential compatibility conflict between WPML and another plugin or the active theme.
Solution:
We recommend testing the latest suggestion provided by our team member, Itamar, which can be found at WPML support forum. If the problem persists, please ensure to continue the discussion in one ticket to avoid duplicated efforts.

Please note that this solution might be outdated or not applicable to your specific case. We highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins. If the issue continues, do not hesitate to open a new support ticket for further assistance.

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Tagged: Exception

This topic contains 7 replies, has 1 voice.

Last updated by Andrey 3 weeks, 6 days ago.

Assisted by: Andrey.

Author	Posts
February 3, 2026 at 5:45 pm #17789259
dianaV-9	Hello WPML Support Team, I would like to follow up on a critical fatal error related to WPML, with additional confirmation from our hosting provider. Error message: Critical Uncaught Error: Maximum call stack size of 8339456 bytes (zend.max_allowed_stack_size - zend.reserved_stack_size) reached. Infinite recursion? File: /wp-content/plugins/sitepress-multilingual-cms/vendor/wpml/fp/core/Fns.php Line: 202 This error occurs repeatedly and causes site instability. Hosting provider investigation (important) We have asked our hosting provider to fully investigate this issue on the server level. After reviewing server-side logs, PHP configuration, and recent system changes, they confirmed the following: This is not a server-side or PHP configuration issue No recent server or PHP updates were made that could cause this behavior PHP version and stack/memory-related settings are correctly configured Modifying zend.max_allowed_stack_size would not be a real solution, as the root cause is an application-level infinite recursion The error clearly points to a logical issue inside the WPML plugin, or a compatibility conflict between WPML and another plugin or the active theme According to the hosting provider, the error indicates that a WPML internal function repeatedly calls itself in an infinite loop, which PHP interrupts for safety reasons. Environment details WordPress: latest stable WPML Multilingual CMS: latest version WPML add-ons: String Translation, Translation Management PHP version: 8.x (confirmed stable and supported by hosting) Hosting: cPanel-based environment Page builder: Elementor No custom code interacting with WPML hooks or filters Observations The error occurs during normal WordPress execution (admin and frontend) It sometimes coincides with WPML-related operations (translations, synchronization) Disabling WPML stops the error entirely (confirmed by testing) Questions Is this a known issue or regression in recent WPML versions? Are there known conflicts between WPML and Elementor that could trigger this recursion? Is there a recommended fix, patch, or workaround, or should we roll back to a specific stable WPML version? We are happy to provide: Full debug logs WPML debug information Temporary admin access if needed Thank you for your assistance — this issue is currently blocking stable operation of the site. Kind regards, Balázs
February 3, 2026 at 5:46 pm #17789264
dianaV-9	{received}
February 3, 2026 at 6:15 pm #17789310
dianaV-9	i need live chat operator pls
February 3, 2026 at 10:16 pm #17789683
Andrey WPML Supporter since 06/2013 Languages: English (English ) Russian (Русский ) Timezone: Europe/Kyiv (GMT+02:00)	Thank you for contacting WPML support. We’ve had similar reports related to the issue you described. Starting with PHP 8.3, the following requirements apply: • zend.max_allowed_stack_size must be at least 256K • zend.reserved_stack_size must be at least 48K Please add or adjust these values in your php.ini file, or contact your hosting provider and ask them to update the settings for you. zend.max_allowed_stack_size = 256K zend.reserved_stack_size = 48K Once these values have been adjusted, could you please recheck the issue and let us know if the problem persists?
February 4, 2026 at 9:01 am #17790321
dianaV-9	Dear Andrey, Thank you for your message. I have added and saved the required PHP 8.3 settings on both websites via cPanel (MultiPHP INI Editor): zend.max_allowed_stack_size = 256K zend.reserved_stack_size = 48K After applying the changes, I cleared all caches and retested, but the critical fatal error / infinite recursion issue still persists. Could you please advise on the next troubleshooting step (e.g., what logs or debug information you would like me to provide)? Best regards, Balazs
February 4, 2026 at 9:09 am #17790416
dianaV-9	When can I expect some help with my 2 websites? It would be very important for the problem to be resolved and for me to finally be able to launch my ads. Because until my website is stable, I cannot run the ads.
February 4, 2026 at 9:47 am #17790544
Andrey WPML Supporter since 06/2013 Languages: English (English ) Russian (Русский ) Timezone: Europe/Kyiv (GMT+02:00)	Thank you for your feedback. I’ll need temporary access to your site (WP-Admin and FTP), preferably to a test or staging site where the issue can be reproduced. When you submit your next reply, you’ll find the private fields below the comment area where you can safely share these credentials. The information you provide there will be visible only to you and to me. Could you also please provide: • The exact steps to reproduce the error. • Where can I find the fresh logs you mentioned In the meantime, I will check with my team about the issue you reported.
February 4, 2026 at 1:15 pm #17791691
Andrey WPML Supporter since 06/2013 Languages: English (English ) Russian (Русский ) Timezone: Europe/Kyiv (GMT+02:00)	Thank you for providing the access credentials. I can see that Itamar is already actively working on the issue you reported. His latest reply is available here: https://wpml.org/forums/topic/critical-fatal-error-infinite-recursion-in-wpml-confirmed-not-server-side-issue/#post-17790758 Could you please test the latest suggestion he provided and let us know the outcome? If the issue persists, I kindly ask you to close one of the tickets and continue the discussion in the other one. This will help us avoid duplicated efforts and keep everything streamlined.