Not sure if this is a packaging issue or a Qt Creator issue. Please move if the installer is not the appropriate place.

The problem is that any WebEngine Widgets example in the beta 3 package cannot be run when opening, configuring and building the example for the first time. It will complain that it cannot find the executable / no executable is set:

Starting /maps.app/Contents/MacOS/maps...
Executable /maps.app/Contents/MacOS/maps does not exist.

There is also a message that the WebEngine widgets module could not be found when configuring the project, although it should be there:

Project ERROR: Unknown module(s) in QT: webenginewidgets

When closing and opening the example again, it will find and run the executable. Configuring and building on the command line works right away. So the workaround for this is to just close and open the project again.