That's weird. That launcher version you have is version 2.0.5-2. They retired the 2.x series a while back, and it's up to version 3.2.x now which will not work without a Qt account. :(

Oh it looks like you obtained that launcher from the old "archives" directory?

http://download.qt.io/archive/online_installers/2.0/

It's unfortunate that only has an old Linux installer. Saw it yesterday, but needed an OSX downloader and was out of luck. :(