Whenever I try to access phpMyAdmin, I receive the following error:
\"The mbstring extension is missing. Please check your PHP configuration.\"
I had this problem for a long time. I found the correct way (for me) to correct it... and it's fairly simple :)
Juste add "universe" on the xenial-updates
# cat /etc/apt/sources.list.d/*
deb [arch=amd64] http://fr.archive.ubuntu.com/ubuntu/ xenial-backports main
deb [arch=amd64] http://fr.archive.ubuntu.com/ubuntu/ xenial main universe
deb [arch=amd64] http://fr.archive.ubuntu.com/ubuntu/ xenial-proposed main
deb [arch=amd64] http://security.ubuntu.com/ubuntu xenial-security main
deb [arch=amd64] http://fr.archive.ubuntu.com/ubuntu/ xenial-updates main **universe**