Resolve Oracle SQL Developer client DB connection issues ORA-00604: error occurred at recursive SQL level 1
ORA-12705: Cannot access NLS data files or invalid environment specified

I was trying to connect to an oracle 11g database with the Oracle SQL Developer client.

But ended up getting below oracle error.

Status : Failure -Test failed: ORA-00604: error occurred at recursive SQL level 1 ORA-12705: Cannot access NLS data files or invalid environment specified

Please note I was using MacOs Catalina, JDK 1.8 and Oracle Sql Deverloper 19.2.1.247 versions.

After several searches and trying out different approaches, I was able to figure out the following solution. Writing down this note since no proper documentation found to the problem.

Open the SQL Developer product.conf file available on

/${UsersHome}/.sqldeveloper/19.2.1/product.conf
Ex. /Users/asankav/.sqldeveloper/19.2.1

In Windows, File should be\sqldeveloper\sqldeveloper\bin\sqldeveloper.conf

And add the following lines:

AddVMOption -Duser.language=en
AddVMOption -Duser.region=us

Now open the Oracle SQL Developer again and try to create a connection.

It's working now …..