This frame should not be. I have disabled all xfce effects. To avoid screen breaks.
Created attachment 8400 Frame at completion.
Sorry, I don't understand what's the problem, do you mean you don't want that frame around logout dialog? If so, I think that was removed since xfce4-session was ported to gtk3.
I do not need the blue color of the window frames, this does not fit with the theme and background, I have not seen this before, because was blue background color.
Moving to the correct product, as I said this seems to have been removed in 4.13.
I have version 4.12. And when can I get an update to the GTK3 version?
It depends on your distribution. On Arch you may use AUR packages, for Debian there is an experimental package, but I couldn't find a PPA for Ubuntu. The other options are to build from source or wait for the 4.14 release. I'm leaving this bug open because I'm not completely sure that frame was removed.
These lines tell me the 6px border around the "window" hasn't been removed: https://git.xfce.org/xfce/xfce4-session/tree/xfce4-session/xfsm-logout-dialog.c#n171 To be honest I'd consider redesigning that dialog a little instead of simply dropping the border.
I dug into the code a bit more and this line is the culprit: https://git.xfce.org/xfce/xfce4-session/tree/xfce4-session/xfsm-logout-dialog.c#n835 I'll remove it and add some css style class on the dialog instead so themes can actually do something with it (e.g. add borders or rounded corners or whatnot).
Simon Steinbeiss referenced this bugreport in commit e50b62fced8bcb12871543bfad3e6ae49638092f Remove blue border from logout dialog (Bug #15284) https://git.xfce.org/xfce/xfce4-session/commit?id=e50b62fced8bcb12871543bfad3e6ae49638092f