If you create a new VMWare host, but then it errors out due to something like smart-proxy DHCP problems, Foreman correctly presents you with this error. However, if the user corrects this problem (fixing permissions on dhcpd.conf, etc) and re-submit, Foreman accepts the host but fails to communicate with VMWare to re-create the guest.

The result is that you have a host in Foreman, but no VM is created in VMWare.