PHP Warning that is null creates an empty shop

Hello,

I have provided a login using a token. The rest of the plugins are disabled.

Let me know if you need anything else.

Best Regards

Unfortunatly no. I hope that you can help me on that one. I only have the debug logs and when the error appears every time I check the shop page there are no products on it and the filter by price does not appear at all. After that, I made the test site, disabled all plugins and left only Woodmart and woocommerce, and the error was still there. No cache was involved. After a while, the products and the price reappeared. So I do not know what is going on except for the warnings above.

The settings that I have on the woocommerce might cause this problem. by enabling the lookup table? That might create conflicts with Woodmart?

That’s all I know so far. except for the warnings with the stack trace that I pasted above.

Let me know if there is something else I can help with.

Best Regards

• This reply was modified 1 year, 7 months ago by supp0rt. Reason: Added some extra information

Would it be possible to add any checks so that if this happens, it should not make the whole shop appear with 0 products?

I am not aware of the theme’s code in-depth and I can see that woocommerce also creates the error here, so I just suggest the above with good faith. if of course, this can work after the implementation.

Best Regards

Ok. I understand that the situation. If I find what is causing this behaviour I will let you know, in case is something that can be added on your end.

Thank you for your time and support.

Best Regards

Hello @admin,

It took me some time to investigate this issue and report back on my ticket.

@admin, I’ve performed extensive debugging and noticed this happens when bots aggressively crawl the site, specifically by exhausting all possible filter combinations. In my case, they were crawling every variation available in the shop. Interestingly, the issue disappeared for about two months but resurfaced today, which suggests that a robots.txt implementation is only a partial workaround and not a definitive fix. (I can provide my robots.txt if needed.)

Below is a snapshot from my logs:

[09-Nov-2025 02:27:51 UTC] [WC-ANOMALY] PHP warn caught: Attempt to read property "query_vars" on null in /[path-to-site]/wp-content/plugins/woocommerce/includes/class-wc-query.php:891 | uri=/shop/?filter_category=christika-antikeimena&filter_fulo=koritsi&filter_hlikia=0-eos-12-minon,18-eos-21-minon,18-eos-99-eton,3-eton-kai-ano,4-eos-6-eton&filter_brands=chillys | referer= | ua=meta-externalagent/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/crawler) | is_shop=yes | is_product_archive=no

[09-Nov-2025 02:27:51 UTC] [WC-ANOMALY] backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/woodmart/woocommerce/archive-product.php'), do_action('woocommerce_sidebar'), WP_Hook->do_action, WP_Hook->apply_filters, woocommerce_get_sidebar, wc_get_template, include('/plugins/woocommerce/templates/global/sidebar.php'), get_sidebar, locate_template, load_template, require_once('/themes/woodmart/sidebar.php'), dynamic_sidebar, WP_Widget->display_callback, WOODMART_Widget_Layered_Nav->widget, WOODMART_Widget_Layered_Nav->layered_nav_list, WOODMART_Widget_Layered_Nav->get_filtered_term_product_counts, Automattic\WooCommerce\Internal\ProductAttributesLookup\Filterer->get_filtered_term_product_counts, WC_Query::get_main_meta_query, {closure}
I investigated whether something interferes with the product query. A key indicator of the problem is that while is_shop is "yes", is_product_archive returns "no".

A var_dump of the SQL query during the error revealed the following:

SQL
SQL: SELECT wp_posts.* FROM wp_posts 
WHERE 1=1 AND (wp_posts.ID = '8') AND wp_posts.post_type = 'page' 
ORDER BY wp_posts.post_date DESC

It appears the main query is being intercepted. Instead of running a product archive query, it defaults to a single page query (fetching the Shop page ID ‘8’). When filter widgets attempt to find products within this “page” context, they find nothing (null), resulting in an empty shop.

Important Note: I noticed that switching to the Storefront theme makes the products reappear immediately. However, this might be a false positive for a permanent fix, as switching themes forces a flush of the rewrite rules and clears transients, which temporarily masks the symptom. The fact that products appear correctly on Category pages but fail on the main Shop page suggests that the conflict specifically affects the Shop’s “Main Query” placeholder handling within the theme.

I have more logs from November if needed, and I am available to provide any further help to debug this.

Just let me know.

Best Regards

@admin

Thank you for your answer. I have set up a staging environment and provided you with access. However, this issue is quite unusual: if we can’t reliably find the source causing it, it might not occur in staging either.

So far, while monitoring the staging environment, I haven’t been able to see the error again. That said, you may have additional insight or steps to reproduce it that I’m missing.

I’ve provided access to the staging environment as well as FTP access.

Thank you.

• This reply was modified 4 months, 1 week ago by supp0rt. Reason: fixed a typo
• This reply was modified 4 months, 1 week ago by supp0rt.

@admin Thank you for your response.

If you are referring to the plugin from Automattic (https://wordpress.org/plugins/jetpack/), it was never installed on the site, and it is also not installed on the production site either. Below, inside the private content, is a list of the currently active plugins on the site. All plugins are currently up-to-date. This also applies to the theme and WordPress.

Let me know if you need anything else.

@admin

Currently happens on the live site. If you are here, I can respond and create an admin login so you can check right now.

I have provided the admin access. At this point, the problem is still there.

Please be carefull this is the live site.

Currently the products are not available again. The shop appears empty.

• This reply was modified 3 months, 3 weeks ago by supp0rt.
• This reply was modified 3 months, 3 weeks ago by supp0rt.
• This reply was modified 3 months, 3 weeks ago by supp0rt. Reason: Typo fix

WP-crontrol is enabled on the site, if you want to also check the cron job and might find anything that I miss.

As far as I know, there are no other tools/cron-jobs that might run in the background or on the server, except for the ones of WordPress. But please let me check, and I will get back to you as soon as possible.