Two errors occur when adding admin to simple forum (after php8.1 upgrade) to accounts table

Hello I.T.,

I am getting two errors, completely replicatable, when I add or delete simple forum admin in the accounts section:

1) E_WARNING: Cannot modify header information - headers already sent by (output started at /home/xxxxxx/public_html/cmsb/lib/errorlog_functions.php:70)
/home/xxxxxx/public_html/cmsb/lib/menus/header.php (line 4)
https://xxxxxxxxxx.com/cmsb/admin.php?menu=accounts&action=edit&num=1

and,

2) E_DEPRECATED: preg_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated
/home/xxxxxx/public_html/cmsb/plugins/simpleforum_1-04/simpleForum/simpleForum.php (line 828)
https://xxxxxxxxxx.com/cmsb/admin.php?menu=accounts&action=edit&num=1

Using CMSB 3.58 (build 2316), AlmaLinux release 8.7, Apache Web Server, php 8.1.18, MariaDB Server v10.6.12, Website Membership 1.14, Simple Forum 1.04

Thank you in advance for your assistance.