Mac Join game issue

I was trying to help friend setup Fantasy grounds on a mac. When we got to the Join game page where you need to type in a user name and server address the cursor wouldn't show up and we couldn't type anything in. I also tried this on my wifes mac and I also had the same issue. Is the a key you need to hit to in put an address?

Hey Fractalhunter and welcome
Try going into settings and either check or uncheck cross platform compatibility - eg try both options.