PHP fatal error in default_menu_walker

Hello @harm10!

Could you please provide your current System Status Report? This will help us further diagnose the issue. Also, could you confirm if you are running a multisite install or a standard single-site setup? Did the error occur immediately after updating to WordPress 6.4.1 from 6.3.2?

Thank you for sharing these details in advance; they will help us better understand the situation.

The status report below is from a multi site but I have similar problems on a single site.
(I removed the site urls from the status report)
I tried upgrading to PHP 8.0 but the problem persists.
These problems occurred directly after upgrading from WP 6.3.2 to 6.4.1.
When reverting to WP 6.3.2 the problem disappears.
I also use Multiple Themes plug-in to display specific pages in another theme. This plug-in was not updated.

` WordPress Environment

WC Version: 8.2.2
REST API Version: ? 8.2.2
WC Blocks Version: ? 11.1.3
Action Scheduler Version: ? 3.6.3
Log Directory Writable: ?
WP Version: 6.4.1
WP Multisite: ?
WP Memory Limit: 256 MB
WP Debug Mode: ?
WP Cron: ?
Language: en_US
External object cache: – Server Environment

Server Info: Apache
PHP Version: 8.0.30
PHP Post Max Size: 32 MB
PHP Time Limit: 30
PHP Max Input Vars: 1000
cURL Version: 7.87.0
OpenSSL/1.1.1p

SUHOSIN Installed: –
MySQL Version: 10.6.15-MariaDB-cll-lve-log
Max Upload Size: 1 MB
Default Timezone is UTC: ?
fsockopen/cURL: ?
SoapClient: ?
DOMDocument: ?
GZip: ?
Multibyte String: ?
Remote Post: ?
Remote Get: ? Database

WC Database Version: 8.2.2
WC Database Prefix: wp_
Total Database Size: 7.48MB
Database Data Size: 4.36MB
Database Index Size: 3.12MB
wp_woocommerce_sessions: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_woocommerce_api_keys: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_woocommerce_attribute_taxonomies: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_woocommerce_downloadable_product_permissions: Data: 0.02MB + Index: 0.06MB + Engine InnoDB
wp_woocommerce_order_items: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_woocommerce_order_itemmeta: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_woocommerce_tax_rates: Data: 0.02MB + Index: 0.06MB + Engine InnoDB
wp_woocommerce_tax_rate_locations: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_woocommerce_shipping_zones: Data: 0.02MB + Index: 0.00MB + Engine InnoDB
wp_woocommerce_shipping_zone_locations: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_woocommerce_shipping_zone_methods: Data: 0.02MB + Index: 0.00MB + Engine InnoDB
wp_woocommerce_payment_tokens: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_woocommerce_payment_tokenmeta: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_woocommerce_log: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_2_commentmeta: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_2_comments: Data: 0.02MB + Index: 0.08MB + Engine InnoDB
wp_2_fa_user_logins: Data: 0.02MB + Index: 0.25MB + Engine InnoDB
wp_2_links: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_2_options: Data: 0.06MB + Index: 0.03MB + Engine InnoDB
wp_2_postmeta: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_2_posts: Data: 0.02MB + Index: 0.06MB + Engine InnoDB
wp_2_termmeta: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_2_terms: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_2_term_relationships: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_2_term_taxonomy: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_2_wpmm_subscribers: Data: 0.02MB + Index: 0.00MB + Engine InnoDB
wp_actionscheduler_actions: Data: 0.02MB + Index: 0.13MB + Engine InnoDB
wp_actionscheduler_claims: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_actionscheduler_groups: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_actionscheduler_logs: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_blogmeta: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_blogs: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_blog_versions: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_commentmeta: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_comments: Data: 0.02MB + Index: 0.09MB + Engine InnoDB
wp_evf_entries: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_evf_entrymeta: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_evf_sessions: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_fa_user_logins: Data: 0.05MB + Index: 0.25MB + Engine InnoDB
wp_links: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_options: Data: 2.48MB + Index: 0.08MB + Engine InnoDB
wp_postmeta: Data: 0.19MB + Index: 0.11MB + Engine InnoDB
wp_posts: Data: 0.09MB + Index: 0.20MB + Engine InnoDB
wp_registration_log: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_signups: Data: 0.02MB + Index: 0.06MB + Engine InnoDB
wp_site: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_sitemeta: Data: 0.03MB + Index: 0.03MB + Engine InnoDB
wp_termmeta: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_terms: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_term_relationships: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_term_taxonomy: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_usermeta: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_users: Data: 0.02MB + Index: 0.05MB + Engine InnoDB
wp_wc_admin_notes: Data: 0.08MB + Index: 0.00MB + Engine InnoDB
wp_wc_admin_note_actions: Data: 0.06MB + Index: 0.02MB + Engine InnoDB
wp_wc_category_lookup: Data: 0.02MB + Index: 0.00MB + Engine InnoDB
wp_wc_customer_lookup: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_wc_download_log: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_wc_orders: Data: 0.02MB + Index: 0.13MB + Engine InnoDB
wp_wc_orders_meta: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_wc_order_addresses: Data: 0.02MB + Index: 0.06MB + Engine InnoDB
wp_wc_order_coupon_lookup: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_wc_order_operational_data: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_wc_order_product_lookup: Data: 0.02MB + Index: 0.06MB + Engine InnoDB
wp_wc_order_stats: Data: 0.02MB + Index: 0.05MB + Engine InnoDB
wp_wc_order_tax_lookup: Data: 0.02MB + Index: 0.03MB + Engine InnoDB
wp_wc_product_attributes_lookup: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_wc_product_download_directories: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_wc_product_meta_lookup: Data: 0.02MB + Index: 0.09MB + Engine InnoDB
wp_wc_rate_limits: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_wc_reserved_stock: Data: 0.02MB + Index: 0.00MB + Engine InnoDB
wp_wc_tax_rate_classes: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_wc_webhooks: Data: 0.02MB + Index: 0.02MB + Engine InnoDB
wp_wpmm_subscribers: Data: 0.02MB + Index: 0.00MB + Engine InnoDB Post Type Counts

acf: 1
acf-field: 2
acf-field-group: 1
attachment: 31
custom_css: 1
everest_form: 1
nav_menu_item: 130
page: 10
post: 21
revision: 3 Security

Secure connection (HTTPS): ?
Hide errors from visitors: ? Active Plugins (16)

Advanced Import: by AddonsPress – 1.4.0
Aki Toolset: by Aki Themes – 1.0.3
Classic Editor: by WordPress Contributors – 1.6.3
Everest Forms: by WPEverest – 2.0.5
IS-theme-companion: by vibhorp – 1.53
WooCommerce: by Automattic – 8.2.2
WordPress Importer: by wordpressdotorg – 0.8.1
LightStart - Maintenance Mode, Coming Soon and Landing Page Builder: by Themeisle – 2.6.8
WP Log Viewer: by Maxwell Berkel – 1.2.1
Really Simple SSL: by Really Simple Plugins – 7.1.3
Reveal IDs: by Oliver Schl?be – 1.6.1
Server IP & Memory Usage Display: by Apasionados
Apasionados del Marketing – 2.1.0

User Login History: by Er Faiyaz Alam – 2.1.3
Advanced Custom Fields: by WP Engine – 6.2.2
WP Rollback: by GiveWP.com – 1.7.3
Multiple Themes: by David Gewirtz – 7.1.1 Inactive Plugins (1)

WP Downgrade | Specific Core Version: by Reisetiger – 1.2.6 Settings

API Enabled: –
Force SSL: –
Currency: EUR (€)
Currency Position: left
Thousand Separator: ,
Decimal Separator: .
Number of Decimals: 2
Taxonomies: Product Types: external (external)
grouped (grouped)
simple (simple)
variable (variable)

Taxonomies: Product Visibility: exclude-from-catalog (exclude-from-catalog)
exclude-from-search (exclude-from-search)
featured (featured)
outofstock (outofstock)
rated-1 (rated-1)
rated-2 (rated-2)
rated-3 (rated-3)
rated-4 (rated-4)
rated-5 (rated-5)

Connected to WooCommerce.com: –
Enforce Approved Product Download Directories: –
HPOS feature screen enabled: –
HPOS feature enabled: –
Order datastore: WC_Order_Data_Store_CPT
HPOS data sync enabled: – WC Pages

Shop base: #737 - /shop/
Cart: #738 - /cart/
Checkout: #739 - /checkout/
My account: #740 - /my-account/
Terms and conditions: ? Page not set Theme

Name: Enigma
Version: 7.59
Author URL: https://infigosoftware.in/
Child Theme: ? – If you are modifying WooCommerce on a parent theme that you did not build personally we recommend using a child theme. See: How to create a child theme
WooCommerce Support: ? Templates

Archive Template: Your theme has a woocommerce.php file
you will not be able to override the woocommerce/archive-product.php custom template since woocommerce.php has priority over archive-product.php. This is intended to prevent display issues.

Overrides: – Admin

Enabled Features: activity-panels
analytics
product-block-editor
coupons
core-profiler
customer-effort-score-tracks
import-products-task
experimental-fashion-sample-products
shipping-smart-defaults
shipping-setting-tour
homescreen
marketing
mobile-app-banner
navigation
onboarding
onboarding-tasks
product-variation-management
remote-inbox-notifications
remote-free-extensions
payment-gateway-suggestions
shipping-label-banner
subscriptions
store-alerts
transient-notices
woo-mobile-welcome
wc-pay-promotion
wc-pay-welcome-page

Disabled Features: customize-store
minified-js
new-product-management-experience
settings
async-product-editor-category-field

Daily Cron: ? Next scheduled: 2023-11-15 13:06:05 +00:00
Options: ?
Notes: 123
Onboarding: completed Action Scheduler

Complete: 9
Oldest: 2023-11-11 11:19:58 +0000
Newest: 2023-11-14 20:35:43 +0000

Failed: 1
Oldest: 2023-06-02 19:10:57 +0000
Newest: 2023-06-02 19:10:57 +0000

Pending: 1
Oldest: 2023-11-15 20:35:43 +0000
Newest: 2023-11-15 20:35:43 +0000 Status report information

Generated at: 2023-11-14 20:47:33 +00:00
`

Hi there,

To diagnose the issue, could you check if the problem persists after disabling the Multiple Themes plugin or all other plugins, for that matter?

I disabled Multiple Themes and made Storefront main theme.
Then the error is gone.

Thank you for the update! I would suggest reaching out to the developer of the Multiple Themes plugin and asking them to test their features with Storefront. If their team requires any additional insights, they are welcome to contact us directly.

I was expecting this……… ??

You can link to this thread or the developer is welcome to contact our developers through the Github repository. We’re happy to offer any guidance if needed.

I contacted the current developer of Multiple Themes. Alas he tells me that he has no time to fix this and advises me to look for another plugin that does the same. I do not think there is an alternative. Just reporting this for those of you who find this.

I also want to add that storefront is not the only one that gets into problems as soon as it is the second theme that needs to be activated.
I am experiencing this with others as well.
All give you a line number in the functions.php of that theme and at that location the first get_template_directory is executed.
I assume the plugin hooks into that function to set the template dir, if desired, to another location when the second theme needs to be activated.

I am trying to understand the logic of the plug-in but haven’t made much progress yet.

It looks like WP 6.4.2 solves the problem! Will test some more (on other sites) and report back.

Hi @harm10

I’m glad to hear that the update to WP 6.4.2 seems to have resolved your issue.

Yes, please continue testing on your other sites and let us know the results. We appreciate your efforts in ensuring the functionality and reliability of the Storefront theme.

If you encounter any challenges or have further questions, don’t hesitate to ask. We’re here to help!

I have updated all my sites that also use Storefront as a secondary theme via Multiple Theme plugin and with WP 6.4.2 there are no problems!

So for me this issue can be closed!