All pages (except homepage) stopped working overnight

Dear Community, I have read all the “Troubleshooting and known issues” info and google for an hours but couldnt find anything. The issue: All pages except homepage stopped working overnight, I get a 404 (not found) error. If I switch the published page to a DRAFT and go the preview it does show, but not when it’s published. I tried:

– deacting my quiz plugin QSM (Quiz And Survey Master)
– updated my theme (kadence), wordpress, plugins
– switching to another theme

I talked the support of my host (Name Hero). This is the result after a long wait (see below).

ANY help would be greatly appreciated!!

Maarten

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Hello,

Thank you for your patience.
We've delved into the issue extensively. A thorough examination involved a mysqlcheck for potential database corruption, replacing WordPress core files with fresh copies, and assessing plugin compatibility through disabling them. Regrettably, the problem persists, and it seems to be related to your Kadence theme. We advise reaching out to the theme support or your website developer for a more in-depth investigation. Our logs have flagged the following error for your reference.

Logs:

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WordPress database error You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ')' at line 3 for query SELECT quiz_id, question_id, answer_array, question_answer_info, question_type_new, question_settings
FROM JAk3r_mlw_questions
WHERE question_id IN () made by require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/kadence/page.php'), do_action('kadence_single'), WP_Hook->do_action, WP_Hook->apply_filters, Kadence\single_markup, get_template_part, locate_template, load_template, require('/themes/kadence/template-parts/content/single.php'), do_action('kadence_single_content'), WP_Hook->do_action, WP_Hook->apply_filters, Kadence\single_content, get_template_part, locate_template, load_template, require('/themes/kadence/template-parts/content/single-entry.php'), get_template_part, locate_template, load_template, require('/themes/kadence/template-parts/content/entry_content.php'), the_content, apply_filters('the_content'), WP_Hook->apply_filters, do_blocks, render_block, WP_Block->render, WP_Block->render, WP_Block->render, WP_Block->render, WP_Block->render, WP_Block->render, qsm_block_render, QMNQuizManager->display_shortcode
[07-Oct-2023 13:06:08 UTC] WordPress database error You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ')' at line 3 for query SELECT quiz_id, question_id, answer_array, question_answer_info, question_type_new, question_settings
FROM JAk3r_mlw_questions
WHERE question_id IN () made by require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/kadence/page.php'), do_action('kadence_single'), WP_Hook->do_action, WP_Hook->apply_filters, Kadence\single_markup, get_template_part, locate_template, load_template, require('/themes/kadence/template-parts/content/single.php'), do_action('kadence_single_content'), WP_Hook->do_action, WP_Hook->apply_filters, Kadence\single_content, get_template_part, locate_template, load_template, require('/themes/kadence/template-parts/content/single-entry.php'), get_template_part, locate_template, load_template, require('/themes/kadence/template-parts/content/entry_content.php'), the_content, apply_filters('the_content'), WP_Hook->apply_filters, do_blocks, render_block, WP_Block->render, WP_Block->render, WP_Block->render, WP_Block->render, WP_Block->render, WP_Block->render, qsm_block_render, QMNQuizManager->display_shortcode
+++++++

The page I need help with: [log in to see the link]