After the most recent patch (a few days ago) it happens always and the old fix won't work:
hardhat:~> gtk-window-decorator
Xlib: extension "RANDR" missing on display ":0.0".
gtk-window-decorator: Screen 0 on display ":0.0" already has a decoration manager; try using the --replace option to replace the current decoration manager.
hardhat:~> gtk-window-decorator --replace
Xlib: extension "RANDR" missing on display ":0.0".
(hang)
I can trigger this like the OP with Java.
After the most recent patch (a few days ago) it happens always and the old fix won't work:
hardhat:~> gtk-window- decorator decorator: Screen 0 on display ":0.0" already has a decoration manager; try using the --replace option to replace the current decoration manager. decorator --replace
Xlib: extension "RANDR" missing on display ":0.0".
gtk-window-
hardhat:~> gtk-window-
Xlib: extension "RANDR" missing on display ":0.0".
(hang)