From Boldcore's wiki
Intro
In vmware ESXi You can get some auto-generated address when creating new VM NIC.
The weird issue
This works just fine, unless You want to import the VM on different host. Then, an error message will appear, saying that the MAC address is reserved.
Solution
Navigate to .vmx file of the VM. Add this to the end of file:
ethernet0.checkMACAddress = "FALSE" ethernet1.checkMACAddress = "FALSE" ethernetX.checkMACAddress = "FALSE" *WHere X is the eth number.