Thanks!
For one reason or another the docking worked now (had been trying for hours before I asked here)

Thanks again for the help!

Thanks for the answers......

The problem is that I cannot dock the attribute pane above or below the elements pane. Next to it is possible, but that eats from the workspace.
Any solution for that?

I have created a custom layout and want to lock the Attribute pane below the Elements pane (or above). It remains floating. - How can I fix it in its right place? - How can I force Oxygen to start up with the custom layout? - How can I freeze the layout, so that it does not change, even if I double ...