When editing the properties of a connection, where does SQL Dev get the values that it uses to populate "Network Alias" drop-list? I always assumed it came from the relevant tnsnames.ora file. In my (our) case, this is a shared file on a server, indicated by setting TNS_ADMIN as a system variable on the Windows desktops.
Yesterday I did some editing of that file, and this morning one of my developers reports an ORA-12514 - listener does not know of requested service. But sqlplus has no issue on the same desktop. It only occurs on one particular db connection.
On my own desktop I use 'basic' connections, but when I tested TNS, I got the same result - this one particular db returns ORA-12514. And what's really curious is when I look at the pick-list, I see every entry repeated, and some entries that do not exist in the shared tnsnames.ora:
