cfx.jar not in class path in ColdFusion for J2EE

I wanted to install a CFX tag and I thought it was going to be a simple thing, since it was something I had done before (obviously not under the J2EE configuration). I entered the information in the administrator, but when running the tag, I would get a nice (and big and bold): 500 com/allaire/cfx/CustomTag

Sure, that tells me a lot, doesn’t it? I knew that the tag implements com.allaire.cfx.CustomTag..., but it didn’t tell me much about the problem.

After trying everything I could think of, I found that the problem was that the file cfx.jar was located at

C:/JRun4/servers/cfusion/cfusion-ear/cfusion-war/WEB-INF/lib

when CF is installed on top of JRun, directory which, due to unknown reasons, is not in the java class path. ColdFusion therefore could not load com.allaire.cfx.CustomTag class and the problem didn’t have anything to do my tag.

The solution was then to add the class path, but thanks to a bug in the JRun Management Console, this could not be done from its Java VM Settings section. It has to be edit directly in the file jmv.config under JRun4/bin (at least that is the path in my configuration). I added

{application.home}/servers/cfusion/cfusion-ear/cfusion-war/WEB-INF/lib

in the section “java.class.path” and everything worked.