Still getting this when trying to connect to the debugger. It works in version 18.4.0.376 but not since they changed the ssh implementation (no longer using PuTty keys version).
I know its the ssh connection in SQL Developer that's the issue because when I use a PuTty session and tunnel to the same port SQL Developer is able to connect. When I use the earlier version 18.4.0.376 SQL Developer is able to connect (this version uses the PuTty gen key format). Both versions 19.4 and 18.4 are able to connect and seemingly establish the remote port, but 19.4 gives the error when trying to debug.
Connecting to the database XXXD1-APPS.
Executing PL/SQL: CALL DBMS_DEBUG_JDWP.CONNECT_TCP( 'localhost', '4001' )
ORA-30683: failure establishing connection to debugger
ORA-12541: TNS:no listener
ORA-06512: at "SYS.DBMS_DEBUG_JDWP", line 68
ORA-06512: at line 1
Process exited.
Disconnecting from the database XXXD1-APPS.
Please fix this issue. Thanks.