There is an annoying regression in the handling of the connections list.
I have a number of connections that include a '/' in the name. Since I upgraded SqlDeveloper I cannot edit these connections. When I save it, it complains that the name is invalid. I have to change it to a "correct" name to save it. But since I have a naming convention I am used to, I have to edit the underlying XML file to put back the '/' according to my naming convention.
The silly thing is that SQL Developer works fine with '/'s in the connection name. There is just that arbitrary rule that won't let me save a connection under that name, even when I update an existing connection and save it under the same name.
So please remove that restriction. which wasn't there in the past, and let people name their connections whatever they like.