If you purchase a used PowerEdge R740 or R750 on eBay, the previous owner may have removed the iDRAC Enterprise license. The license is tied to the Service Tag, but the owner can transfer it via Dell’s portal.
How to check a used server:
Even with a valid key, you might encounter issues. idrac 9 license key
Error 1: "License XML signature verification failed" If you purchase a used PowerEdge R740 or
Error 2: "License already imported"
Error 3: "License version mismatch"
This is the default state for most PowerEdge servers. It is included with the hardware at no additional cost. Error 2: "License already imported"