Installation Problem with linux

1. Brekeke Product Name and version:
Brekeke sip server 2.1.6.6
2. Java version:
JDK 1.5
3. OS type and the version:
CentOS release 5.2
4. UA (phone), gateway or other hardware/software involved:
Plesk 8.6 hosting panel
5. Select your network pattern from http://www.brekeke-sip.com/bbs/network/ ... terns.html :

6. Your problem:
we have installed the sip server on Plesk 8.6 where tomcat 5.2.25 is running and setup is installed successfully. but when i open /proxy i got following error

java.lang.NullPointerException
org.apache.jsp.InputLicense_jsp._jspService(Unknown Source)
org.apache.jasper.runtime.HttpJspBase.service(jasper5-runtime-5.5.23.jar.so)
javax.servlet.http.HttpServlet.service(tomcat5-servlet-2.4-api-5.5.23.jar.so)
com.brekeke.web.Bean.forward(Unknown Source)
com.brekeke.web.Bean.display(Unknown Source)
com.brekeke.web.Bean.execute(Unknown Source)
com.brekeke.web.Bean.go(Unknown Source)
com.brekeke.web.Bean.go(Unknown Source)
com.brekeke.sipadmin.web.Login.exec(Unknown Source)
com.brekeke.web.Bean.execMain(Unknown Source)
com.brekeke.web.Bean.execute(Unknown Source)
com.brekeke.web.Bean.go(Unknown Source)
com.brekeke.web.Bean.go(Unknown Source)
com.brekeke.sipadmin.web.InputLicense.exec(Unknown Source)
com.brekeke.web.Bean.execMain(Unknown Source)
com.brekeke.web.Bean.execute(Unknown Source)
com.brekeke.web.Bean.go(Unknown Source)
com.brekeke.web.Bean.go(Unknown Source)
com.brekeke.sipadmin.web.Login.exec(Unknown Source)
com.brekeke.web.Bean.execMain(Unknown Source)
com.brekeke.web.Bean.execute(Unknown Source)
com.brekeke.web.Bean.go(Unknown Source)
com.brekeke.web.Bean.startBean(Unknown Source)
com.brekeke.web.GateServlet.performTask(Unknown Source)
com.brekeke.web.GateServlet.doGet(Unknown Source)
javax.servlet.http.HttpServlet.service(tomcat5-servlet-2.4-api-5.5.23.jar.so)
javax.servlet.http.HttpServlet.service(tomcat5-servlet-2.4-api-5.5.23.jar.so)

Can You please point me where is the problem. its Urgent.

Thank You.

Are you using a pre-installed Java??
If so, you may need to get the latest Java from Sun's website and install it.