When I click on Install App, nothing happens
I solved this issue by doing the following


Turn on the Debug Menu in the App Store using

defaults write com.apple.appstore ShowDebugMenu -bool true

Using the Debug Menu, clear cookies and reset the application
Open the Downloads directory and delete the com.apple.appstore folder
Quit the App Store and kill the storeagent process
Try to install again


I had to do the above steps a couple times before I got it to work.