I don't use the pro version. I think that's only needed if you have 4 webcams for each computer, for studios or something like that.
With the regular version I can transmit to as many sites as I want plus OBS and Skype all at the same time so no need to use Pro.
I guess Pro will still work, not sure, but if your activation doesn't work they will have to fix that for you. I usually get a reply from their support within 24 hours. I believe that they are only open during the day Russian time.