Ubuntu 17.10: Upgrade from xorg to wayland: window decorations broken!

Today i upgraded my ubunto from 16.04 to 17.10:

 

Up to this step everything worked fine.

But after the reboot i got tiny window decorations. This had to do with some further changes to the unity desktop - i used compiz there and this broke the new wayland configuration.

I found some hints about

dpkg --purge compiz-plugins ...

but this did not really help.
The way out was this:

mv .compiz .compiz.old
mv .gconf .gconf.old
mv .config .config.old

After moving such old configuration directories the desktop looked ok.
For changing the windows decorations i had to install

 apt install gnome-tweak-tool

Sorry, that i do not post any screenshot of the new 17.10 desktop - but the screenshot application does not work anymore ;-)