I connect to a database with read only access using SQL developer. It's a TNS connection. I use a tnsnames.ora, forwarding port script and SQL Developer. In the past, occasionally, when connecting, I get a error message Got a minus one from a read call. Vendor Code 0 If I do a reboot, it goes away. Another friend suggested changed the forwarding port which worked for him. I recently upgraded to a new computer and now it seems that I am getting the error message consistently. Reboot or changing forwarding port does not help at all. The port forwarding script contains something like this putty -L ::1521 Does anybody have any idea? Thanks.