VMware vSphere Client Error

Hi please see the error i get when i try to connect to the virtual and this started after we switch from ADSL to Fibre.
All the other server did work and we have internet but the virtual server is not working and i can't even Ping that IP address.
what i did is i disconnect the D-link Dsl router and connect our Lan and server cables to our Dell POE Switch the internet from Microtic switch to our dell switch as well.

Can you please explain to me how i can fix this and i'm not good at Networking i'm a Desktop support but i manage our servers as well please??.

 

So, how are you handling your IP scheme, i.e. how are IP addresses allocated within the network? Do you have a DHCP server? What about static IPs?