Can't move windows anymore

[Jerome Yuzyk <jerome@xxxxxxxxxxxxxx>]

[KDE 4.14.30 on Fedora 25]

The darnedest thing: suddenly I can't move a window by grabbing the title bar. 
Neither full height windows nor dialogs. Others have reported this, but mostly 
in past releases. It seems I need to kill the kwin process and restart it with 
"kwin --replace". Failing that, logout and back in. I'd rather not do that.

First off, I don't have a "kwin" process, though I do have a "kwin_x11" 
process. Secondly, is "kwin --replace" the right way to start kwin?