PHP UpGrade Level Up to 8.0 from 7.4 – Debugging the website rendering problem

Links

• WordPress PHP Compatibility
• Common PHP v8.1 Compatibility Fixes for WordPress
• WordPress Debugging

Theme related

• WordPress themes
• Underscores theme – blog example 
• How to Find Out What WordPress Theme a Site is Using

php Related

• PHP – Supported Versions
• Change the PHP version of a site
• PHP upgrade failure troubleshooting

Steps

1. Running on Php 7.4 – went to 8.0 – does not work – flagged by email that comment editor plug in errored out. Current plugin: Mihdan: Ajax Edit Comments (version 6.1)
2. Disabled Plugin == Current plugin: Mihdan: Ajax Edit Comments (version 6.1)  – result was a partial rendering of individual webpages.  Header was there content not.  Backend interface rendered
3. Since backend rendered – changed theme to default and this errored out with Php=8.0 – error email received with link for "recovery mode"
4. Changed theme back to Hestia and reverted to PHP=7.4
5. Updated Hestia theme – went to php=8.0 and again rendered partial same as step #2.   
6. reverted to php 7.4
7. Added code to function.php to  eliminate related pages in Hestia theme.  All functioning normally again at this point.
8. Used PHP compatibility scanner plug in.  See results below
9. Disabled the list of plug ins – set Php = 8.0 and site rendered – Trouble was with rendering base URL page not blog entries.
10. set php = 8.1 ( recommended ) and site rendered
11. WP-FileManager plugIn errored out  – disabled
12. CUSTOMIZE / Widgets / Header / Background /  – on left menu errors out – claims to send email – none received – This is due to residual problem with CKEditor.  Disabling CKEditor plugin allows these items to render

List of disabled plug ins

• Mihdan: Ajax Edit Comments  1st round – confirmed problem – deleted
• Optimal Title  2nd round – reversed and still worked
• Register Plus   2nd round – reversed and still worked
• Search Excerpt   2nd round – confirmed problem – deleted
• Yoast SEO Premium   2nd round – reversed and still worked.
• WP-Filemanager – 3rd round – disabled.

Conclusion

Had I paid closer attention to what rendered and what did not I would have seen a clue to which plugin was causing the issue.  Individual posts were rendering but the top index page was not. This is where Search Excerpts plugin was used.  This with the following assumption:

• Themes are unlikely in recent versions to cause php compatibility issues.  

Original Email

NOTICE: It's not too late to upgrade PHP!

Hi

Our latest scans show that at least one of your websites is still running an outdated, unsupported version of PHP:

amarketplaceofideas.com (PHP v7.4)

As mentioned in previous emails, all websites with unsupported PHP versions are required to also have our PHP Extended Support service on their account. PHP Extended Support will be added to your account on July 27, 2023 if no changes are made.

PHP Extended Support is an additional $5.00 monthly charge per account and will be automatically removed when all of your sites have upgraded to a supported version of PHP. This service allows us to hire the staff required to keep outdated versions of PHP available for your websites and build tools to help you successfully keep your PHP up to date.