Using sql developer 3.2.20.09
Don't know what I clicked accidentally, my dbms output window is screwed up. I can not see its top end . So I can not close it or see /change the db connection. Only thing I can do with this window is to change its size from bottom edge or from sideways.
Thanks and Regards,
You could try minimising or moving some other panes to make the top of the dbms_output pane visible.
Failing that, you could delete windowinglayout.xml which will reset the windows to the defaults.
The file should be in SQL Developer\system3.2.20.09.87\o.ide.220.127.116.11.37.59.48 in your home directory (.sqldeveloper if not on windows