No authorized routine named “SQLJ.INSTALL_JAR” of type “PROCEDURE” having compatible arguments was found

My goal is to deploy a Java routine to a DB2 server. After reading Deploying Java routine class files to DB2 database servers on p.267-268 of IBM DB2 10.5 for Linux, UNIX, and Windows Developing User-defined Routines (SQL and External) I issued the following call in IBM Data Studio:

call sqlj.install_jar('file:/C:/Projects/javadb2.jar', 'javadb2'); 

where C:/Projects/javadb2.jar is the path on the DB2 server machine to the JAR to be deployed to its local filesystem. It throws the following error:

No authorized routine named "SQLJ.INSTALL_JAR" of type "PROCEDURE" having compatible arguments was found.. SQLCODE=-440, SQLSTATE=42884, DRIVER=4.18.60

I tried under the regular user and under db2admin to no avail. The only question that I found for this error on SE was where they added a 3d parameter, so this is not my case. Anyhow, with or without the 3d parameter of 0, it still fails with the same error message.