If there happens to be an abnormal exit from ENERCALC SEL, the program is set up to fail-safe and return the activation to the Internet Activation server. This helps to prevent the situation where activations get tied up in "limbo" and are inaccessible to users.
If you have chosen the "Indefinite" activation option, and if you are presented with an activation dialog when you launch the program, simply activate the software and continue using the program.