Ubuntu - Unable to configure manual network config

I’m unable to configure a template is vSphere with Ubuntu 18 LTS.
At the Network Connections screen I insert the subnet and the IP, it returns me the error “ is not contained in”
Does anyone know how it’s possible to make it work? We don’t have a DHCP in-place in this domain.


The support gurus in our support venues https://community.ubuntu.com/t/finding-help/712 are awaiting your networking question.

Unfortunately, this is not the right place for support. Sorry.