This article explains error code 3640 that can be received when activating or re-activating a software license.
When activating or re-activating a software license the customer receives the following error message:
Your license cannot be activated at this time. Please wait a while and try again. If this problem persists then please contact Solatech. (3640).
This is caused when there are no more free activation slots for the license. This can happen if a license is reset but the activation slot it was using was not removed and an empty one added.
To resolve you must identify the activation slot that is no longer being used, by referencing the Product ID's, remove that slot and add a new one back.
Note: This can also happen if a user is trying to install/activate the software on more computers then they are supposed to.