Upgrade from 13.1.1 to 15.0.3 problem

[Simon Quill]

I have just performed the upgrade from 13.1.1. to 15 .0.3, but have run in to a problem.

https://quills-queries.org.uk/index.php

I can access the admin section, the home page and some of the site pages, but others give an HTTP ERROR 500.

https://quills-queries.org.uk/surnames.php

The server is running PHP 8.3

The quills-queries_org_uk.php.error.log is filling up with the following:

[02-Dec-2025 13:01:53 UTC] PHP Fatal error:  Uncaught Error: Call to undefined function mb_convert_encoding() in /home/quillsqu/public_html/quills-queries/log.php:41
Stack trace:
#0 /home/quillsqu/public_html/quills-queries/famsearch.php(329): writelog('<td class="data...')
#1 {main}  thrown in /home/quillsqu/public_html/quills-queries/log.php on line 41

But I don't know if that is related.

Any suggestions on where I should look gratefully received.

[JLH]

Maybe the php-mbstring extension is not installed in your PHP 8.3. Your host will probably be able to help you.

Jean-Luc

[Simon Quill]

Thank you Jean-Luc,

That appears to have solved the problem.

Simon Quill.