Hi.

in the process of upgrading from 2.26.4 to 2.27.1:

Checking URL to installation    POSSIBLE PROBLEM
Web page at 'https://xxxxx.com/' does not appear to be a MantisBT site.
The system will not function properly if this URL is not accessible.

in address bar: https://xxxxx.com/admin/install.php

in config.php:
$g_path = 'https://xxxxx.com/';

but the upgrade process itself went without any errors.

then after clicking https://xxxxx.com/my_view_page.php

INTERNAL APPLICATION ERROR

in nginx logs:

2025/03/20 16:29:41 [error] 1368#1368: *8 FastCGI sent in stderr: "PHP message: array_merge(): Argument #1 must be of type array, null given
/var/www/job/my_view_inc.php: 282: - - - - array_merge()
/var/www/job/my_view_page.php: 155: - - - - include( <string>'/var/www/job/my_view_inc.php' )" while reading response header from upstream, client: 192.168.66.37, server: xxxxx.com, request: "GET /my_view_page.php HTTP/2.0", upstream: "fastcgi://unix:/var/run/php/php8.1-fpm.sock:", host: "xxxxx.com", referrer: "https://xxxxx.com/admin/install.php"

EDIT (dregad): fix markdown