JRun - Troubleshooting "error Could not pre-load servlet: MessageBrokerServlet"

Evironment
- JRun4 + Update6
- LCDS2


I have installed JRun4 already but couldn't run the server. So I search on the Internet about the error and I found the solution. I updated JRun server using Update6. However this time another error ocurred, so I coudn't the server again. Again, thanks to the Internet I got some hint to solve my situation. The error I have met like the picture below:

JRun uses apche API to handle log and this message was that JRun found some same libraries under the JRun directory relating to processing loggin in form of .jar file. The name of library is commons.logging.jar to handle logging.
So I searched the files like below:

I got rid of all highlited files except one. Only valid one is located under default.

Now, it works.