The message "The product key has been activated the maximum number of times" indicates that the license has already been activated twice. As such, you will need to deactivate an activation from within the program, or using your web browser:  

• How Do I Deactivate My Single-User Golden Software License? 
• How Do I Deactivate My Concurrent-Use Golden Software License? 

The following could cause you to see "The product key has been activated the maximum number of times":

• You have already activated two other computers with this product key. Each license comes with two activations, so you cannot install and activate the software on three computers.
• You reinstalled or reimaged Windows before deactivating the license. Now you have an orphaned activation.
• The computer crashed/died/was replaced. Now you have an orphaned activation.
• One of the three locking criteria (MAC Address, the processor ID, and Windows UUID) changed on your computer to cause the previously activated license to be invalid. These locking criteria lock the license to the computer. If any of those change, that activation is no longer valid and the license must be activated again. The previous license becomes orphaned.

Additional resources:

• I Installed The Product And Activated The License In The Admin Account, But I'm Prompted For The PK When I Log Into My User Account. Why?
• How Do I (IT Admin) Install And Activate The Software For Use On Another User Account? 

Updated April 15, 2019