Upgrade Ubuntu 16.04 to 18.04 on Zabbix Server with version 4.2

[Pradish]

I am looking for some guidance and support on upgrading Ubuntu 16.04 to 18.04 with Zabbix version 4.2 installed.
This is in preparation to upgrade Zabbix 4.2 to 5.0

Looking at some posts, members have ran into problem when they did Ubuntu OS upgrade on exsisting Zabbix server....

[MarcArbour]

Hi Zabbix experts.

We are running 7 copies of preconfigured images of Zabbix 2.0.9 (OpenSuse I think) servers on a very well and very large secured network.

My question is: how should we go about upgrading the OS on these machines? Are upgrades at all necessary or should...