Are you using more seats than you own? If you own one seat, you can install and activate one seat on one computer. Two seats for two computers. And so on. You cannot activate and use more seats than you own. The LTU is to move an activated license for one computer to another computer. But it does not entitle you to use more seats than you own. If you wish to install more clients than seats owned, then you should consider the network licensed version. The license manager will handle usage.