I try to use SQL Developer 4.1 (JDBC 1.3.1) to conncet SQL Server Express 2014.
I use hostname=localhost and port = 1433/OAE;instance=SQLEXPRESS (OAE is my DB)
My error message is in french, but I think is "Test failure - Impossible to connect to server Microsoft SQL Server on localhost"
The TCP/IP protocol for SS is enable; I use Windows authentication.
Thanks for the help.