My system is MX-Linux 21/64 bits. After upgrade php7.4 to 8.1 myphpadmin stopped working. Shows blank page and after I cheked the error log of the apache2 I saw that error:
[Thu Jul 13 00:05:25.647833 2023] [php:error] [pid 1231] [client 127.0.0.1:48414] PHP Fatal error: Uncaught Error: Call to undefined function PhpMyAdmin\\mb_strpos() in /usr/share/phpmyadmin/libraries/classes/Url.php:257\nStack trace:\n#0 /usr/share/phpmyadmin/libraries/classes/Url.php(208): PhpMyAdmin\\Url::getArgSeparator()\n#1 /usr/share/phpmyadmin/libraries/classes/Url.php(171): PhpMyAdmin\\Url::getCommonRaw()\n#2 /usr/share/phpmyadmin/libraries/classes/Core.php(765): PhpMyAdmin\\Url::getCommon()\n#3 /usr/share/phpmyadmin/libraries/classes/Core.php(338): PhpMyAdmin\\Core::linkURL()\n#4 /usr/share/phpmyadmin/libraries/classes/Core.php(367): PhpMyAdmin\\Core::getPHPDocLink()\n#5 /usr/share/phpmyadmin/libraries/classes/Core.php(995): PhpMyAdmin\\Core::warnMissingExtension()\n#6 /usr/share/phpmyadmin/libraries/common.inc.php(110): PhpMyAdmin\\Core::checkExtensions()\n#7 /usr/share/phpmyadmin/index.php(23): require_once('...')\n#8 {main}\n thrown in /usr/share/phpmyadmin/libraries/classes/Url.php on line 257
I have purged and reinstalled php8.1, installed also 7.4 and reinstalled phpmyadmin. When I installed phpmyadmin I noticed that php8.2 installed automatically. I have searched the net for similar issues, but couldn't find any working solution.