This usually means that the license for ExtendSim was successfully activated or deactivated in our online activation database, but the message the database returned (an encrypted text file) got blocked by your system.
When this happens, manual activation is required. ExtendSim will present a dialog so you can generate a text file for manual activation/reactivation. Click the button to generate a text file (ExtendSim Activation Info.txt). By default, that file will be placed at the top of your Documents folder. Email the text file to Sales.ExtendSim@Andritz.com.
We will process your activation manually and email your license file back to you.