Restore the external connection end point ID
This section provides instructions for restoring the Nintex external connection end point ID (formerly Nintex Live ID) that was noted from the SharePoint 2013 environment before beginning the upgrade.
To restore the Nintex external connection end point ID
On the Central Administration Home page, click Nintex Administration and then click External connection settings under Licensing and setup.
Select the check box Override ID and then update the existing value with the ID noted from the SharePoint 2013 environment.