Getting PHP Fatal error whenever the update post

Hi Julian, thanks for reporting. Will look into the issue asap ??

I’ve not been able to reproduce the issue but the error seems to indicate that the core sitemap is being loaded from the admin on each post save. This is not default WP behaviour (as far as I know) so here are some follow-up questions: what other plugins are you using? what is you WP version?

We are on the latest WP version with PHP8.1. The client has many plugins; on their rank math, they have disabled the sitemaps function.

wp-core
version: 6.4.3

wp-active-theme
name: Zox News (zox-news)
version: 3.9.0 

wp-mu-plugins (1)
Index WP MySQL For Speed Upgrade Filter for mu-plugins.: author: (undefined), version: 1.4.11 

wp-plugins-active (65)
Advanced Ads: version: 1.51.0
Advanced Ads Pro: version: 2.26.0
Advanced Ads – AMP Ads: version: 1.12.1
Advanced Ads – Google Ad Manager Integration: version: 2.4.0
Advanced Ads – Tracking: version: 2.6.0
Advanced Database Cleaner PRO: version: 3.1.0
All In One WP Security: version: 5.2.7, author: All In One WP Security & Firewall Team
Better Image Credits: version: 2.0.3
Bulk Move: version: 1.3.0
C3 Cloudfront Cache Controller: version: 6.1.5
Classic Editor: version: 1.6.3
Code Embed: version: 2.3.8
Color Mobile Browser Address Bar: version: 1.0.10
Dable for WordPress: version: 3.3.2
Disable Comments: version: 2.4.5
Elementor: version: 3.19.3 
Elementor Pro: version: 3.19.3
EWWW Image Optimizer: version: 7.3.0
GN Publisher: version: 1.5.13
GTM4WP - A Google Tag Manager (GTM) plugin for WordPress: version: 1.20
Head, Footer and Post Injections: version: 3.2.7
Index WP MySQL For Speed: version: 1.4.15
MalCare WordPress Security Plugin - Malware Scanner, Cleaner, Security Firewall: version: 5.47
Mashshare Share Buttons: version: 4.0.42
Menu Icons: version: 0.13.9
Meta pixel for WordPress: version: 3.0.15
Molongui Authorship: version: 4.7.9
MonsterInsights - Dimensions Addon: version: 2.1.0
MonsterInsights Pro: version: 8.24.2
MVP Themes Social Buttons: version: 1.0
MWW Scheduled Post Trigger: version: 3.2
Nextend Social Login: version: 3.1.12
NextScripts: SNAP Pro Upgrade Helper: version: 2.0.3
NextScripts: Social Networks Auto-Poster: version: 4.4.3
Nginx Helper: version: 2.2.4
oEmbed Plus: version: 1.6
OG — Better Share on Social Media: version: 3.3.0
Pre-Publish Checklist: version: 1.1.3
Quiz Cat Business: version: 3.0.6
Rank Math SEO: version: 1.0.213
Rank Math SEO PRO: version: 3.0.37
Redirection: version: 5.4.2
Redis Object Cache: version: 2.5.0
Security Headers: version: 1.1
Simple Posts Ticker: version: 1.1.6
Speaker: version: 4.0.3
SSL Insecure Content Fixer: version: 2.7.2
Super Socializer: version: 7.13.63
User Profile Picture: version: 2.6.1
User Role Editor: version: 4.64.2
Webpushr Push Notifications: version: 4.35.0
Widget Options: version: 4.0.0
WP Add Custom CSS: version: 1.1.6
WP Coder: version: 3.5
WP Crontrol: version: 1.16.1
WP Edit: version: 4.0.4
WP Extended Search: version: 2.1.2
WP File Manager: version: 7.2.2
WPForms Lite: version: 1.8.6.4
WP Mail SMTP: version: 3.11.1
WP Maps: version: 4.5.6
WP Rollback: version: 2.0.6
WP Sticky Sidebar: version: 1.3.9
XML Sitemap & Google News: version: 5.4.5

Owww, impossible to say where the conflict is coming from. The only way to find out more is to disable all other plugins or even switch to a default theme… Do you have a dev/staging site?

If not, then it would be easier to try the the Plugin sitemap server instead of the Core server. Go to Settings > XML Sitemap and set Server: Plugin.

Let me know ??

Hi @julians3 could you try the latest version 5.4.6 and let me know if you still encounter the problem?

Hey, thank you so much for the update. Is working fine now~