Oracle ESB -Designtime cache has not been initialized

I got this error just after installing the ESB DesignTime(Repository) component on SOA Suite when I called up http://localhost:7777/esb

I looked in the logfiles for the oc4j instance hosting esbdt

In my case at
D:\SOAHA\soaONE\j2ee\oc4j_esbdt\log\oc4j_esbdt_OC4J_ESBDT_1\oc4j\log.xml

The error message was as follows -

java.lang.NoClassDefFoundError: org/apache/log4j/Category))

The workaround is as follows -

Add the following line to the orion-application.xml file for esbdt

(remove-inherited...)