We've recently upgrade some of our databases to 12c:
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
However I find irregular behaviour when compiling existing packages. Most of the time the compile itself will be instantaneous, and I can see the code has changed. But the "show errors" that also appears in the script takes a long time to respond, or doesn't come back.
It took me writing this post to realise it's probably the "show errors". If I remove this command from the package script and try to run it manually, I get the same problem.
After cancelling whatever the request is attempting, my session will typically no longer respond nor I cannot reconnect/disconnect. I need to force shutdown of SQL Developer and reopen.
This occurred in SQL Developer 4.1.2 and I've just upgraded to 4.1.3 and issue remains.
It only appears to happen in one of our two 12c instances. All on Windows.
Scott.