I just upgraded from Xubuntu 19.10 to 20.04. This moved me from php 7.3 to php 7.4.3 and phpmyadmin 4.9.5+dsfg1-2.
Everything was working prior to the upgrade. Now, I can successfully access a test php web page and I can display the PHP_info.php page. However, when I try to access phpmyadmin, it throws a fatal error recorded in the apache2 error log file. Here it is, expanded for readability:
[Tue Sep 15 20:15:09.030096 2020] [php7:error] [pid 2092141] [client ###.###.###.###:53310]
PHP Fatal error: Uncaught Error:
Call to undefined function PhpMyAdmin\\mb_strpos() in /usr/share/phpmyadmin/libraries/classes/Url.php:253
Stack trace:
#0 /usr/share/phpmyadmin/libraries/classes/Url.php(206): PhpMyAdmin\\Url::getArgSeparator()
#1 /usr/share/phpmyadmin/libraries/classes/Url.php(169): PhpMyAdmin\\Url::getCommonRaw()
#2 /usr/share/phpmyadmin/libraries/classes/Core.php(749): PhpMyAdmin\\Url::getCommon()
#3 /usr/share/phpmyadmin/libraries/classes/Core.php(330): PhpMyAdmin\\Core::linkURL()
#4 /usr/share/phpmyadmin/libraries/classes/Core.php(353): PhpMyAdmin\\Core::getPHPDocLink()
#5 /usr/share/phpmyadmin/libraries/classes/Core.php(973): PhpMyAdmin\\Core::warnMissingExtension()
#6 /usr/share/phpmyadmin/libraries/common.inc.php(106): PhpMyAdmin\\Core::checkExtensions()
#7 /usr/share/phpmyadmin/index.php(27): require_once('/usr/share/phpm...')
#8 {main}
thrown in /usr/share/phpmyadmin/libraries/classes/Url.php on line 253, referer: http://<server>/html/admin.html
How is it that the function mb_strpos() is not defined?
Any suggestions on how to address this?