I have the same issue. However I am using an iMac with xfinity wifi as my connection, so no hard wired internet.
The Magicjack was working until the last Apple update. It used to fail at every update and the solution was to shut the iMac down, pull out all the plugs, including power, let it sit a bit. Then fire it up again with nothing attached at the USB bus and do a parameter ram zap double dong at startup.
Then the Magicjack used to be seen, the splash screen came up and I was back in business.
Since this last update, I cannot get the dial window to connect to the internet. It says connect to the internet and double click here. Problem is, I am connected to the internet and double clicking does nothing.
Not sure if this is a MagicJack or Apple issue, but have to look for something else other than Magic Jack. Totally unreliable. Even the Microsoft corrupted Skype works better.
Stay tuned. Have a concierge session with MagicJack tomorrow. Maybe there is another firmware update they haven't told us about.