Comment 2 for bug 1683345

initial situation: Ubuntu 16.04 with 7 Package updates en 7 security updates waiting
After clean boot Ubuntu suggests to update to 16.04.2 with do-release-upgrade

from sudo-user I did
sudo update
sudo do-release-update

during release update Ubuntu asked me to use the new file for release-update
Old file: /etc/apt/apt.conf.d/50unattended-upgrades root.root 0644
New File: /etc/apt/apt.conf.d/50unattended-upgrades.ucftmp root.root 0644
I accepted the new file

after release-update Ubuntu finished with errors;

"Errors were encountered while processing:
 mysql-server-5.7
 mysql-server
Error in function:"

After clean reboot the Zabbix frontend (webGUI) didn't work anymore and gave the following error:
"Configuration error
--------------------
DB type "MYSQL" is not supported by current setup
Possible values."

Logging into mysql gave a lot of errors when reading config so I tried to stop mysql service, which took very long.
I then stopped the zabbix-server service, apache2 service and then again mysql service. After a few min it stopped. Then I started the previous mentioned services again but the same problem.
Then I logged into mysql and tried to repair database. After that I could succesfully read config.
Zabbix frontend still gave the same error.
After that my collegue did the following to correct the problem:
as sudo-user: sudo apt-get install php-mysql (which according to him installed php7 for mysql upgrade). After that he also fixed some more things (sorry don't know details)

Problem is solved now