Environment
GroupWise Mailbox Management 18.0.1.81

Situation
GWMM requires that the GroupWise system name be provided when the license file is created in order to work.

Resolution
There is a way to do this via the Software License Download (SLD) portal.  You can specify this when activating the entitlement:

After selecting Activate, a screen is presented where the Target name can be specified:

Click on Add and enter the GroupWise System name exactly as it appears inside the GroupWise Admin console.  This will generate the .pem license file that will then be able to be used inside the stand alone Mailbox Management application.

See Tid https://portal.microfocus.com/s/article/KM000009030?language=en_US