On PSIfusion 188.8.131.52 or earlier, the 'Install Offline License" button may not be displayed in Deployment Manager.
This is because the OfflineRequest.xml file is not in the right location.
Deployment Manager is looking for a file called OfflineRequest.xml in the deployment's directory (e.g. C:\ProgramData\PSIGEN\Fusion\Deployments\Test). If the file is in that directory, the Install Offline License button will be displayed. This file is generated when you initially perform an offline license request. It might store it there automatically, or it might bring up a browse dialog box and if the user directs it outside of this location, the button will not be available.
Make sure when attempting to activate PSIfusion 184.108.40.206 or earlier, that you name the offline XML file to "OfflineRequest.xml" and place it in the Deployment Directory prior to launching Deployment Manager.