"VMM Server" is not a valid network computer name.
Only fully qualified domain names and NETBIOS computer names are valid. An IP address is valid only for hosts on a perimeter network, ESX hosts, and hosts joined to the domain by using an IPv6 address. Check the computer name, and try the operation again.
Here, "VMM Server" is name of the management server of SCVMM.
To address this problem,
1. Check DNS entry for that host
2. Check /etc/hosts file of the host for any incorrect static entries.
In my case, No.2 was my problem that incorrect static IP was input in the hosts file.