Cloning a server to save time is possible, but it will break the license system if too many settings are different.
This is the process:
IF MAC addresses are different
AND the system hard drive IDs or machine names are different
THEN the new hardware configuration is invalid (too many changes detected)
OTHERWISE IF the MAC addresses are different
AND the IP addresses are different
AND the machine names are different
THEN the new hardware configuration is invalid (too many changes detected)
To know which one, nothing could be easier: you have to activate the application logs (AdminTool) and open the AdminTool. The log file will contain the reasons why the license is invalid.