Can't install MSWord Grammar Checker app for Studio 2015

After downloading the .exe file for this app and clicking on it, a screen appears with the title "Welcome to the SDL plugin installer wizard", yet there's no button on it or anything else that I could click on in order to proceed with the installation. The 2014 version works just fine, it's only the 2015 version that gives me this issue. Any ideas? Thanks in advance!