To enable Debug Logging for the Qlik Sense License Service:
Stop the QlikSenseServiceDispatcher service.
Make sure in Task Manager > Process tab > there is NO "Qlik Licenses Service" running (which indicate that the service has been killed). If you see there is "Qlik Licenses Service" running, please kill/end that process.
Go to C:\Program Files\Qlik\Sense\ServiceDispatcher
Open services.conf
Locate the [licenses.parameters] section
Add the line -log-level=debug
Restart/Start the QlikSenseServiceDispatcher service