The enterprise license can't be used per the license agreement once it has expired, or the customer will be in breach of the license agreement.
Here is an excerpt from the license agreement:
"6. TERM AND TERMINATION.
This License becomes effective on the date you accept this License and will continue until terminated as provided for in this License.
If you have any specific questions regarding your license, or renewals, etc please contact your sales rep or send an email to info@nxlog.org .