No one have tryed to upgrade teres to Ubuntu 18.4 LTS?
I tried and succeeded! :-)
But not with do-release-upgrade.
I replaced the distro codename "xenial" with "bionic" in /etc/apt/sources.list and ran "apt full-upgrade".
great idea I will give it a try
WIFI & Battery charge icon applet disappear... HDMI does not work indeed, bluetooth not workinng here.
Not great problems overall.
Adding "Indicator Applet (Complete) Factory" to panel made WiFi and other icons appear for me.
Regarding the battery indicator after upgrading to 18.04, it seems UPower peer the battery with the keyboard for some reason. In other words, it thinks it's the battery of the keyboard and not of the computer.
I guess it's due to a bug in the kernel driver, but I'm too lazy to check.
Here is the patch I applied on upower to work around the problem:
Upgraded successfully to 18.10 Cosmic the same way.
Upgraded successfully to 19.04 Disco the same way.
Upgraded successfully to 19.10 Eoan the same way.
do-release-upgrade could also succeed, but it needs some more free space on the boot partition, which is quite small, retained from the original image. This is also valid for the intermediate upgrade attempts, whose GUI appears in the desktop environment, as they try to upgrade the kernel.