Error when trying to delete user CB 4.2 RC1

HI. When i try to delete a user. it goes to a blank page and shows error 500. Here is the output form the browser:

Request URL: https://10.209.78.241/admin_area/members.php?deleteuser=6006
Request Method: GET
Status Code: 500
Remote Address: 10.209.78.241:443
Referrer Policy: no-referrer-when-downgrade
cache-control: no-store, no-cache, must-revalidate
content-length: 0
content-type: text/html; charset=UTF-8
date: Mon, 15 Jun 2020 18:49:42 GMT
expires: Thu, 19 Nov 1981 08:52:00 GMT
pragma: no-cache
server: Apache/2.4.43 (codeit) OpenSSL/1.1.1g PHP/7.2.31
set-cookie: pageredir=https%3A%2F%2F10.209.78.241%2Fadmin_area%2Fmembers.php%3Fdeleteuser%3D6006; expires=Mon, 15-Jun-2020 20:49:42 GMT; Max-Age=7200; path=/
status: 500
x-powered-by: PHP/7.2.31
:authority: 10.209.78.241
:method: GET
:path: /admin_area/members.php?deleteuser=6006
:scheme: https
accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,/;q=0.8,application/signed-exchange;v=b3;q=0.9
accept-encoding: gzip, deflate, br
accept-language: en-US,en;q=0.9
cookie: PHPSESSID=t6f3f2lhc2cst3ui5ju11fjrq2; quick_list_box=show; sess_salt=3af00; pageredir=https%3A%2F%2F10.209.78.241%2Fadmin_area%2Fmembers.php
referer: https://10.209.78.241/admin_area/members.php
sec-fetch-dest: document
sec-fetch-mode: navigate
sec-fetch-site: same-origin
sec-fetch-user: ?1
upgrade-insecure-requests: 1
user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.97 Safari/537.36
deleteuser: 6006

Everything else on the site works. I am just unable to delete users.

System config:
CB 4.2 RC1
CentOS 7
MySQL: Ver 15.1 Distrib 5.5.65-MariaDB
Apache 2.4.43
PHP 7.2.31

Thanks in advance.

PHP and database version compaitibility issue.