Yikes! If I read this right this is a post from 2012. The new QtCreator (5.1) works out of the box with Android for Windows--and I assume Linux (I have not tested on Ubuntu).
http://qt-project.org/wiki/Category:Developing_Qt::Ports::Android
This is basically part of the IDE now.
There's a lot of possibilities for why you get that message. Did you compile for ARM5/6/7? What are you emulating? Does it have the right CPU set up? I'd take a clean install of Creator bundled so you eliminate the possibility of your local setup and run the example Android applications. This, again, works well for me on Windows which was well behind the curve on this latest release.
And yes, the documentation is really lacking right now on this front. It took me the better part of 3 hours to get it working with the emulator. One of the steps was to launch the emulator form the SDK then try connecting from my debugger.