If the computer that you installed your plugin on does not have an Internet connection, you will need to perform an "offline authoriztaion." Follow these steps:
Enter the email address and serial number of the license you wish to download.
Transfer your license file to your "offline" computer using a USB key or other portable device.
Save the license file to the following folders on your offline computer:
Note: If you installed your plugin into a different set of folders, save the license file to those folders instead.
After restarting your DAW, and with the license file in the correct folders, your plugin should be authorized. When you open the plugin editor, the authorization screen should no longer appear.