Devices do not appear in app

Hello, I am using this on two desktop computers and it works.

I have just installed it on a new laptop for traveling, and when I login to the management console on the website, the two devices appear there. When I click on Connect, the app pops up as usual, but it does not give me a drop down list with those two devices - the list is empty. How can I get it to give me a choice of those two existing computers?