The DeskArtes 3Data Expert programs use the network interface MAC addresses as ID numbers for the license.
The problem appears usually when there is a network adapter with a dynamic MAC address, meaning that the adapter is not always connected to the machine or its MAC address is just changing. If the license is created for that kind of MAC address, the license only works when the MAC address is available on the system.
The solution is to select a more stable MAC address in the list of System ID numbers, shown with the "Help->Licenses: Show ID details" command, and order a license code for that ID. Usually the MAC addresses of the Ethernet controller and the Wireless network adapter on the machine motherboard are most stable.
When a license code is installed with the "Help->Licenses: Install license code" command, the license code is saved into a file under the system ProgramData folder.
If the user account, used for installing the license, does not have write access right to that folder, the installation fails and the error message is shown.
One solution to this is to use a user account with administrative rights to install the license.
In some cases a better way is to install the license code manually to the file using the Windows Notepad program.