Fatal error after updating from PHP 8.5.9 to 8.5.12

[CTaylor]

Hello,

I am encountering an issue after I upgrade to php version 8.5.12 from 8.5.9. I get the fatal error below when accessing the website. I can point IIS back to 8.5.9 and it works fine. I had previously tried updating to 8.5.11 and it has the same issue. Is there anyone that could help or point me in a direction?

XenForo version: 2.3.12
Server software: Microsoft-IIS/10.0
All addons disabled.

Fatal error: Uncaught Error: Call to undefined function mb_internal_encoding() in C:\XenforoRoot\src\XF.php:140 Stack trace: #0 C:\XenforoRoot\src\XF.php(114):
XF::standardizeEnvironment() #1 C:\XenforoRoot\index.php(15): XF::start('C:\\XenforoRoot') #2 {main} thrown in C:\XenforoRoot\src\XF.php on line 140

Relevant lines from XF.php file:
111 public static function start ($rootDirectory)
112 {
113 self::bootstratp($rootDirectory);
114 self::standardizeEnvironment();
115 self::startAutoloader();
116 self::setupClassAliases();
117 self::startSystem();
118 }
~
130 public static function standardizeEnvironment()
131 {
~
140 mb_internal_encoding('UTF-8');


Relevant line from index.php:
15 \XF::start($dir);

 

[CTaylor]

Nevermind,

I didn't enable mbstring in the new php.ini file. It's been resolved.