I have multiple Flarum installations for testing purposes. When I first install version 1.8.x and then upgrade to 2.x, I don’t encounter any issues. However, when I install 2.x directly via SSH, I run into a problem.
By the way, both the phpinfo file and the Flarum settings show that the PHP version is 8.3. In fact, there are no errors shown in the system information obtained from the Flarum admin panel. There are also no issues with my other Flarum installations.

The error is:
PHP Warning: Undefined array key 1 in /vendor/flarum/core/src/Extension/Extension.php on line 97
public static function nameToId(string $name): string
{
[$vendor, $package] = explode('/', $name);
$package = str_replace(['flarum-ext-', 'flarum-'], '', $package);
return "$vendor-$package";
}
Maybe I’m missing something, but even though I have 4 different Flarum installations on the same server, all running on PHP 8.3, I only encounter this issue on one specific site.
php flarum info:
PHP Warning: Undefined array key 1 in /vendor/flarum/core/src/Extension/Extension.php on line 97
Flarum core: 2.0.0-beta.8
PHP version: CLI: 8.3.30, Web: 8.2.30 (MISMATCH - versions should match!)
PHP memory limit: CLI: 128M, Web: 128M
MySQL version: 10.11.16
Loaded extensions: Core, date, libxml, openssl, pcre, zlib, bz2, calendar, ctype, hash, filter, ftp, gettext, gmp, json, iconv, SPL, pcntl, random, readline, Reflection, session, standard, mbstring, SimpleXML, sockets, tokenizer, xml, mysqlnd, bcmath, curl, dba, dom, enchant, fileinfo, gd, imagick, imap, intl, ldap, exif, mysqli, odbc, PDO, pdo_mysql, PDO_ODBC, pdo_pgsql, pdo_sqlite, pgsql, Phar, posix, pspell, redis, soap, sodium, sqlite3, sysvmsg, sysvsem, sysvshm, tidy, xmlreader, xmlwriter, xsl, zip, Zend OPcache
+--------------------------+---------------+--------+-------+
| Flarum Extensions | | | |
+--------------------------+---------------+--------+-------+
| ID | Version | Commit | Notes |
+--------------------------+---------------+--------+-------+
| flarum-flags | v2.0.0-beta.8 | | |
| flarum-approval | v2.0.0-beta.8 | | |
| flarum-tags | v2.0.0-beta.8 | | |
| flarum-suspend | v2.0.0-beta.8 | | |
| flarum-subscriptions | v2.0.0-beta.8 | | |
| flarum-sticky | v2.0.0-beta.8 | | |
| flarum-statistics | v2.0.0-beta.8 | | |
| flarum-nicknames | v2.0.0-beta.8 | | |
| flarum-messages | v2.0.0-beta.8 | | |
| flarum-mentions | v2.0.0-beta.8 | | |
| flarum-markdown | v2.0.0-beta.8 | | |
| flarum-lock | v2.0.0-beta.8 | | |
| flarum-likes | v2.0.0-beta.8 | | |
| flarum-gdpr | v2.0.0-beta.8 | | |
| flarum-extension-manager | v2.0.0-beta.8 | | |
| flarum-emoji | v2.0.0-beta.8 | | |
| flarum-bbcode | v2.0.0-beta.8 | | |
+--------------------------+---------------+--------+-------+
Base URL: https://badges.huseyinfiliz.com
Installation path: /badges
Queue driver: database
Session driver: file
Scheduler status: Never run
Mail driver: log
Debug mode: off