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.