Has anyone else experienced this? Fairly frequently I find that kwin
on F25 is not starting on login, there are no window decorations (e.g.
title bar) and all new windows start at top left with no apparent way
to move them. The solution seems to be to start a console and run
"kstart kwin".
I've got that from time to time.
What I do is: go to a console session with Ctrl+Alt+F2, login as root, reboot.
I use the nouveau driver.
Frédéric