I've been using SQL Developer 4.1EA2 in Mac OS X 10.10.2. After upgrading to Mac OS X 10.10.3, I can no longer open any connection. SQL Developer 4.0.3.16.84 works fine in Mac OS X 10.10.3.
When opening a connection, a dialog box pops up that says "Your database connection has reset. Any pending transactions or session state has been lost". After clicking OK, the same dialog box keeps popping up repeatedly until SQL Developer is force quit (normal quit does not work at that point).
To reproduce:
1. Create a new database connection
2. Click Test to verify connection info is correct
3. Click Connect, behavior is as described above
SQL Developer version 4.1.0.18, Build MAIN-18.37
Oracle JDK 1.8.0_40.