Call to undefined function __() error - phpMyAdmin

For Debian users: (I ended up in this thread as a Debian user) I read @naveen 's answer and it appeared I didn't have php-mbstring installed, installing it solved my problem:

sudo apt-get install php-mbstring

(After installing php-mbstring, don't forget to restart Apache:)

sudo systemctl restart apache2

Check that your session directory is writable by the webserver process.

The best way to do so is to create your own phpinfo file; in any web accessible folder create a file (you can call it test.php or phpinfo.php or whatever you'd like) with the following content:

<?php
phpinfo();
?>

Open that file in your browser (http://localhost/test.php or similar) and look for the line session.save_path. That's your session folder; make sure the permissions are suitable and see if that helps.

More information from a similar thread.

I just set up CentOS 7 and tried phpmyadmin and was having the same problem. Hope this helps

I set the correct permissions to the sessions directory and restarted apache, even disabled SELinux but was shown the same error

I did not have the php-mbstring installed - once i did that, it worked

sudo yum install php-mbstring

Check the requirements for phpmyadmin