With VMWare introducing ESXi and VCentre 6.7 recently and with them stopping support on older versions of ESXi, it is very easily to lose track of what version of VCentre can talk to what version of VMWare. To address this I threw together a quick compatibility table.

It is no surprise that older versions of VCentre cannot talk to newer versions of ESXi, the upgrade process should always start with VCentre but, if you’re running older versions of VMware be aware that from 6.7, you cannot run any version of ESXi older than 6.0 and I know that’ll catch many people out.
You can run two VCentres but watch out for licensing, as chances are that you are only legally licenced for one.
Additionally, anything older than 5.5 is end of life and 5.5 goes end of life itself on September 19th, 2018.