Right click on the browser and run as Admin, see if that helps out.
You can check and see if the Kalydo Player installed by going to the Installed Programs option in the Control Panel.
Does the white screen say "Loading" with a swirly image?
You may have the UAC prompt that is waiting for you to authorize the Kalydo Player to install and run.
It's pretty disconcerting when you are doing great the first 3-4 stages of the campaign, then go against an opponent who uses nothing but elite ninjas and siege towers when you haven't even come up against those unit types yet and your cards consist of 99% Recruit units.
When you level up and you are going to assign skill points, if you're trying to level up a skill you already have unlocked, it's hard to click on it because it keeps thinking I want to drag it. I usually end up having to click it about 10 times before it brings up the dialog to level it up.
Right click on the browser and run as Admin, see if that helps out. You can check and see if the Kalydo Player installed by going to the Installed Programs option in the Control Panel.