The following notice has been posted to the official GLSetup homepage, explaining why users are getting errors when running the web version of GLSetup:

Build 107 has expired!
Unfortunately, the current build has expired and will pop up a dialog box to that effect when you run GLSetup. We're working on a new build with updated drivers and bug fixes and will have it ready in the very near future, but we didn't get it done and tested in time to avoid the expiration, so please continue to use Build 107 and "Continuing" through the expiration boxes.