Project Init Panel defaults to unusable layout after fresh install

After a fresh install of Qt 4.15.0-beta2 I started the new QtCreator for a first time with a given .pro- file in the command line:

qtcreator myproject.pro

As the project was also checked out freshly there was no .pro.user file.

QtCreator jumps to the project setup panel, but the listing of the Kits is filling the whole space, while the parametrization is squeeched to the right without any visible content.