Then that is the issue, maybe there are some problem with the server/ net connection, i assume it will check the Serial someplace before it let you go further on.
Have you try'd to just close it and make sure you have net Connection before try again, and this time as admin, and it dont need to be in your place, so maybe at a later time/ next day.
Or maybe just close and start you pc again ( not restart )
V18, V19, V20, V21, 2015/ 16/ 17/ 18 Pro. Platinum
Deluxe V20, V21, 2015/ 16/ 17
Windows 10 Home Premium 64 bit, 32 GB
NVIDIA Geforce GTX 780m, 1 GB