[FIXED] How to fix phpMyAdmin Fatal error: Uncaught TypeError: mb_strtolower() expects parameter 1 to be string

Issue

PhpMyAdmin causes error while executing a query:

SELECT * FROM users u 
    INNER JOIN address a ON u.userid=a.id
    INNER JOIN  health_status h ON u.userid=h.uid
    WHERE u.userid='1634627411'

SELECT * 
from users u 
    INNER join friends f on u.userid=f.user 
    inner join friends f1 on u.userid = f1.friend 
WHERE f.user="1634627411"

Both the query throws error

the error:

Fatal error: Uncaught TypeError: mb_strtolower() expects parameter 1 to be string, null given in /Applications/XAMPP/xamppfiles/phpmyadmin/libraries/classes/Display/Results.php:3095 Stack trace: #0 /Applications/XAMPP/xamppfiles/phpmyadmin/libraries/classes/Display/Results.php(3095): mb_strtolower(NULL) #1 /Applications/XAMPP/xamppfiles/phpmyadmin/libraries/classes/Display/Results.php(2772): PhpMyAdmin\Display\Results->getRowInfoForSpecialLinks(Array, Array) #2 /Applications/XAMPP/xamppfiles/phpmyadmin/libraries/classes/Display/Results.php(2613): PhpMyAdmin\Display\Results->getRowValues(Object(mysqli_result), Array, 0, Array, Array, '', Array, 'SELECT * FROM u...', Array) #3 /Applications/XAMPP/xamppfiles/phpmyadmin/libraries/classes/Display/Results.php(4219): PhpMyAdmin\Display\Results->getTableBody(Object(mysqli_result), Array, Array, Array, false) #4 /Applications/XAMPP/xamppfiles/phpmyadmin/libraries/classes/Sql.php(1364): PhpMyAdmin\Display\Results->getTable(Object(mysqli_result), Array, Array, false) #5 /Application in /Applications/XAMPP/xamppfiles/phpmyadmin/libraries/classes/Display/Results.php on line 3095

I already tried this questions answer.

My phpmyadmin version is also up to date 5.1.1

What's the error mean and how to solve it?

Solution

You need to upgrade your phpMyAdmin version. Version 5.1.1 is not compatible with PHP 8.1.

As of posting, the new version doesn't seem ready yet, so for the time being downgrade to PHP 8.0.

Answered By - Dharman