On the Spirent TestCenter the license files are installed on the chassis. It is installed in the Spirent TestCenter application | Tools | Licensing Management window.
If you have more than one license files installed, please check that you do not have any expired demo licenses. The application may read off an expired demo license which will restrict you from running a test. If there is an expired license installed, we recommend to delete it.
Before you delete you licenses 1) back up all licenses (click Upload), 2) then delete the all licenses from the chassis. Then install the valid licenses for the chassis. You can reinstall your permanent license and a valid demo license. However do not install expired demo license files.