Here is how I solved the:
The phpMyAdmin configuration storage is not completely configured, some extended features have been deactivated. To find out why click here.
Connection for the controluser as defined in your configuration failed.
Looked here for the post on how to fix it.
For my Ubuntu 16 I used this code:
sudo wget --no-check-certificate https://raw.githubusercontent.com/skurudo/phpmyadmin-fixer/master/pma-ubuntu.sh && sudo chmod +x pma-ubuntu.sh && sudo ./pma-ubuntu.sh