If the issue persists after trying the above, open a support case with Microsoft Volume Licensing Support.
: Confirm you aren't trying to apply a Standard Edition key to a server that requires Enterprise Edition , or vice versa. You can check your current edition using: Get-ExchangeServer | Format-List Name, Edition, *Trial* . exchange 2019 product key invalid
If the Set-ExchangeServer command returns "Invalid key," proceed to Step 4. If the issue persists after trying the above,
Even after entering a valid key, the server might not reflect the "Licensed" status until critical background services are manually refreshed. How to Resolve the Error 1. Use Exchange Management Shell (PowerShell) Exchange may demand a GVLK
Your Windows Server OS is activated via KMS, but you are trying to enter a MAK key into Exchange. Exchange inherits the activation context of the OS. If Windows is KMS-activated, Exchange may demand a GVLK, not a MAK.