We recently upgraded from Windows 7 to Windows 10 and from Oracle 10g to 12c. I never had this issue with my SQL Developer in the old environment. With the old version, when a connection timed out, it would tell you it timed out and then you could reconnect. With the new version, if I walk away for lunch when I come back the whole application is frozen and won't even allow me to close it. I have to kill it from the Task Manager. Any ideas?
you upgraded everything BUT SQL Developer
3.2 is from 2012. Go get version 17.4. And be happy, very happy