openam modify server port not working - port

Question

My Env:
OpenAM V11
apache-tomcat-7.0.54
Win7 Pro
Sun JDK 1.7.0_55
I refer to below guide to change server port
http://docs.forgerock.org/en/openam/10.1.0/admin-guide/index/chap-change-hosts.html
Firstly I export the config, make a copy of exported config. Then modified the file and import back.
What I changed:
changing the port number value of com.iplanet.am.server.port.
replace port number in host:port combinations throughout the file.
After import back to openam and restart tomcat. OpenAM is not longer working and here are the tomcat log.
I can't figure out the problem thus I just roll back to using init exported copy.
Any help?
[Tomcat log]
INFO: ContextListener: attributeAdded('org.apache.jasper.compiler.TldLocationsCache', 'org.apache.jasper.compiler.TldLocationsCache#4cdd13d9')
Jul 23, 2014 1:42:17 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [LoginServlet] in context with path [/openam] threw exception [AMSetupFilter.doFilter] with root cause
java.lang.NullPointerException
at java.util.regex.Matcher.getTextLength(Unknown Source)
at java.util.regex.Matcher.reset(Unknown Source)
at java.util.regex.Matcher.<init>(Unknown Source)
at java.util.regex.Pattern.matcher(Unknown Source)
at org.forgerock.openam.upgrade.UpgradeUtils.parseVersion(UpgradeUtils.java:334)
at org.forgerock.openam.upgrade.UpgradeUtils.isVersionNewer(UpgradeUtils.java:280)
at org.forgerock.openam.upgrade.UpgradeUtils.isVersionNewer(UpgradeUtils.java:276)
at com.sun.identity.setup.AMSetupFilter.doFilter(AMSetupFilter.java:101)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2442)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2431)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)