After installing and activating AdminStudio and restarting the machine, you may lose connection to the FlexNet license server. When this occurs, you may receive the error below. 

This issue occurs because the Flexnet administrator website (http://localhost:8090/) is not reachable after the machine restart, and one of the services responsible for loading the Flexnet Administrator website failed to start.

Solution

To correct this, you can manually run the executable.

1. Go to C:\Program Files (x86)\Flexera Software\FlexNet\Licensing Server\lmadmin.exe.

2. Double-click on lmadmin.exe, and it flashes a black screen.
3. Refresh or reload the browser (http://localhost:8090/), and you should be able to access the FlexNet Administrator website.