To resolve an "invalid" product key error in Exchange Server 2019 , the most effective solution is typically to Exchange Management Shell (EMS) instead of the graphical Exchange Admin Center (EAC) Microsoft Community Hub Primary Solution: Use PowerShell (EMS)
If everything above fails:
Get-ExchangeServer | fl Name, Edition, AdminDisplayVersion, IsExchangeTrialEdition Use code with caution. Copied to clipboard 3. Check for Trailing Spaces exchange 2019 product key invalid
If the key is confirmed to be corrupt or mistyped on the license certificate, request a replacement key through the Microsoft Volume Licensing Service Center (VLSC). To resolve an "invalid" product key error in
Re-enter the key carefully. Better yet, copy the key directly from VLSC and paste it into the EAC. To paste into the product key field, use Ctrl + V or right-click. Solution: Re-enter the key carefully
for the change to take effect: Restart-Service MSExchangeIS . 2. Common Causes for Invalid Key Errors