Indeed, this is repeatable in the 1.2.0 version of Designer Studio, but only when opening a ".pro" file, opening one of the project's QML file, and then running Live Preview.
In fact, I have the same exact problem on everything: Windows, Linux and macOS.
I do not have any
.qt-license file in any of these above OSes. I'll post a bug as I suspect this is indeed a bug.