Having changed to a 64-bit development machine at work recently I ran into an Oracle error while trying to generate files using CodeSmith. This error was ORA-06413: Connection Not Open. Assuming it was a connection string error, as I had not run this particular generation in some time and it was likely that the server or username/password had changed, I proceeded to test the connection from SQL Developer. Success!
After ruling out that the connection was indeed valid I did a quick Google search for the error message. After a few clicks I discovered a very well known (has been around for a few years) Oracle issue; When executing an Oracle command from an application with parentheses or equals — ‘(‘ or ’)’ or ‘=’ — in the path than the specified error message is thrown.
In this particular case, CodeSmith had been installed under C:/Program Files (x86)/CodeSmith which was causing Oracle to fail. The quickest workaround was to simply move CodeSmith from the Program Files (x86) path e.g. into C:/CodeSmith. However; there is a patch (5383042) for Oracle 10g, which is also applied to Oracle 11G.