Critical error - gzuncompress

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

Problem:
The client is experiencing a critical error when trying to access the backend administration of their website after enabling the

gzuncompress

function, which was previously disabled on their server.
Solution:
We recommend enabling WordPress debugging to identify the specific error causing the critical issue. Here are the steps to follow:
1. Edit the

wp-config.php

file on your server.
2. Add the following lines before the comment /* That's all, stop editing! Happy publishing. */:

define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false );

3. Replicate the error by trying to access the backend again.
4. Check the

debug.log

file located in the /wp-content/ directory for any WPML-related errors.
5. Copy and paste the full error message back to us for further analysis.

If this solution does not resolve your issue or seems irrelevant due to being outdated or not applicable to your case, we highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent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. Additionally, if you need further assistance, please open a new support ticket at WPML support forum.

This is the technical support forum for WPML - the multilingual WordPress plugin.

Everyone can read, but only WPML clients can post here. WPML team is replying on the forum 6 days per week, 22 hours per day.

Tagged: Exception

This topic contains 3 replies, has 0 voices.

Last updated by Andrey 1 week, 1 day ago.

Assisted by: Andrey.

Author	Posts
April 16, 2026 at 9:29 pm #17975493
martinZ-12	Hello, I have a problem (critical error) with translating the website > gzuncompress on server is disabled (php_admin_value[disable_functions] = gzuncompress) When I enable the gzuncompress, the is no way to see backend administration > critical error. Could you help me please?
April 17, 2026 at 7:28 am #17976065
Andrey WPML Supporter since 06/2013 Languages: English (English ) Russian (Русский ) Timezone: Europe/Kyiv (GMT+03:00)	Thank you for contacting WPML support. If you still get a fatal error, we need to know what it's about. Here are the steps: 1. Enable WordPress debugging by editing your wp-config.php file. Add (or modify, if these lines already exist) the following lines before the comment /* That's all, stop editing! Happy publishing. */: define( 'WP_DEBUG', true ); define( 'WP_DEBUG_LOG', true ); define( 'WP_DEBUG_DISPLAY', false ); 2. Replicate the error. 3. Check the debug.log file (located in the /wp-content/debug.log) for any WPML-related errors. 4. Copy and paste the full error message here.
April 18, 2026 at 7:27 am #17977786
martinZ-12	Hello Andrey, in debug.log isn't any error. But I get an email: Podrobnosti chyby ================= Na řádku č. 430 v souboru /www/hosting/lamajja.cz/www/wp-content/plugins/sitepress-multilingual-cms/vendor/otgs/installer/src/Recommendations/RecommendationsManager.php došlo k chybě typu E_ERROR. Chybová zpráva: Uncaught Error: Call to a member function get_subscription() on null in /www/hosting/lamajja.cz/www/wp-content/plugins/sitepress-multilingual-cms/vendor/otgs/installer/src/Recommendations/RecommendationsManager.php:430 Stack trace: #0 /www/hosting/lamajja.cz/www/wp-includes/class-wp-hook.php(341): OTGS\Installer\Recommendations\RecommendationsManager->getRecommendationNotices() #1 /www/hosting/lamajja.cz/www/wp-includes/plugin.php(205): WP_Hook->apply_filters() #2 /www/hosting/lamajja.cz/www/wp-content/plugins/sitepress-multilingual-cms/vendor/otgs/installer/includes/admin-notices/notices/Recommendation.php(30): apply_filters() #3 /www/hosting/lamajja.cz/www/wp-includes/class-wp-hook.php(341): OTGS\Installer\AdminNotices\Notices\Recommendation::getCurrentNotices() #4 /www/hosting/lamajja.cz/www/wp-includes/plugin.php(205): WP_Hook->apply_filters() #5 /www/hosting/lamajja.cz/www/wp-content/plugins/sitepress-multilingual-cms/vendor/otgs/installer/includes/admin-notices/Loader.php(31): apply_filters() #6 /www/hosting/lamajja.cz/www/wp-includes/class-wp-hook.php(341): OTGS\Installer\AdminNotices\Loader::initDisplay() #7 /www/hosting/lamajja.cz/www/wp-includes/class-wp-hook.php(365): WP_Hook->apply_filters() #8 /www/hosting/lamajja.cz/www/wp-includes/plugin.php(522): WP_Hook->do_action() #9 /www/hosting/lamajja.cz/www/wp-admin/includes/class-wp-screen.php(424): do_action() #10 /www/hosting/lamajja.cz/www/wp-admin/includes/screen.php(243): WP_Screen->set_current_screen() #11 /www/hosting/lamajja.cz/www/wp-admin/admin.php(217): set_current_screen() #12 /www/hosting/lamajja.cz/www/wp-admin/index.php(10): require_once('...') #13 {main} thrown
April 20, 2026 at 1:45 pm #17981273
Andrey WPML Supporter since 06/2013 Languages: English (English ) Russian (Русский ) Timezone: Europe/Kyiv (GMT+03:00)	Thank you for your feedback. I need to request temporary access (wp-admin and FTP) to your site—preferably to a test site where the problem has been replicated if possible—in order to be of better help. When you log in to leave your next reply, you will find the needed fields below the comment area. The information you will enter is private, meaning only you and I can see and access it. Provide the exact steps to reproduce the issue. Please also install the Adminer plugin if I need to check your database.