Hello,
You mentioned its auto-populating? Where are you seeing this? You can also try breezing through the installer using the "Free" action then applying your actual license once you log into SmarterStats. If you have a license.json file in C:\Program Files (x86)\SmarterTools\SmarterStats\MRS\App_Data\Config, you could try deleting it and re-running the install. This will clear your current license, which would make it not auto-fill or anything which means you'll wanna have your key ready to re-license.
Matt Petty
Senior Software Developer
SmarterTools Inc.
www.smartertools.com