Error in phpmyadmin Warning in ./libraries/plugin_interface.lib.php#551

Just edit the plugin _interface.lib.php

sudo gedit /usr/share/phpmyadmin/libraries/plugin_interface.lib.php

Find this line

if ($options != null && count($options) > 0) {

Add (array) or replace with this

if ($options != null && count((array)$options) > 0) {

This problem also occurs when you have an older version of phpMyAdmin which may not play well with newer PHP versions.

TO solve the issue:

1) Download the latest version of phpMyAdmin from https://www.phpmyadmin.net/.

2) Unzip the downloaded folder.

3) Copy all it's content to /usr/share/phpmyadmin.

Be sure all matching files and folders are being replaced with new ones (those you downloaded).

4) Restart apache: sudo systemctl restart apache2

All will work.