When I click on "Download" on my license, the overlay window opens. I select the appropriate version and activate the checkbox. i clicke "Download"... Overlay closes - that's it.
@au lait I've had reports of this from some users, but haven't tracked down what is causing this. Please try going into the individual licence page details, and use the download button there.
I think it may be a client side pop-up blocker or script blocker being responsible.
unlikely, have used the same add-on years without problems. I also tried with 4 other browsers.
by the way just tried again - without problems. Very strange.