Unable to deploy server configuration using server configuration tool while setting up IBM Mobilefirst 7.1

I am trying to setup IBM Mobilefirst v7.1 on Ubantu 14.04. I have java version "1.8.0_131" trying to configure it with tomcat7.
Application Center is working fine.

when I am trying to deploy server configuration using server configuration tool I am getting an error log is as follows.

Buildfile: /root/.mobilefirst_platform_server/server-configuration-tool/Configuration_SALESDEMO/SALESDEMO.xml

adminstall:
[installworklightadmin] Logging output of task <installWorklightAdmin> to file /root/.mobilefirst_platform_server/configuration-logs/installWorklightAdmin_2017_06_19_08_42_30.log
[installworklightadmin] java.lang.NullPointerException
[installworklightadmin]  at com.ibm.worklight.config.ant.appserver.AppServerTask.getBackupFileNextId(AppServerTask.java:6358)
[installworklightadmin]  at com.ibm.worklight.config.ant.appserver.AdminAppServerTask.makeTomcatJMXRMIEnvScript(AdminAppServerTask.java:1029)
[installworklightadmin]  at com.ibm.worklight.config.ant.appserver.AdminAppServerTask.buildAndProcessItems(AdminAppServerTask.java:1142)
[installworklightadmin]  at com.ibm.worklight.config.ant.appserver.AppServerTask.setupBuildAndProcessItems(AppServerTask.java:3064)
[installworklightadmin]  at com.ibm.worklight.config.ant.appserver.AppServerTask.doExecute(AppServerTask.java:307)
[installworklightadmin]  at com.ibm.worklight.config.ant.appserver.InstallWorklightAdminTask.execute(InstallWorklightAdminTask.java:43)
[installworklightadmin]  at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:292)
[installworklightadmin]  at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
[installworklightadmin]  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[installworklightadmin]  at java.lang.reflect.Method.invoke(Method.java:498)
[installworklightadmin]  at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
[installworklightadmin]  at org.apache.tools.ant.Task.perform(Task.java:348)
[installworklightadmin]  at org.apache.tools.ant.Target.execute(Target.java:435)
[installworklightadmin]  at org.apache.tools.ant.Target.performTasks(Target.java:456)
[installworklightadmin]  at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1393)
[installworklightadmin]  at org.apache.tools.ant.Project.executeTarget(Project.java:1364)
[installworklightadmin]  at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
[installworklightadmin]  at org.apache.tools.ant.Project.executeTargets(Project.java:1248)
[installworklightadmin]  at org.apache.tools.ant.Main.runBuild(Main.java:851)
[installworklightadmin]  at org.apache.tools.ant.Main.startAnt(Main.java:235)
[installworklightadmin]  at org.apache.tools.ant.launch.Launcher.run(Launcher.java:280)
[installworklightadmin]  at org.apache.tools.ant.launch.Launcher.main(Launcher.java:109)

BUILD FAILED
/root/.mobilefirst_platform_server/server-configuration-tool/Configuration_SALESDEMO/SALESDEMO.xml:74: java.lang.NullPointerException
 at com.ibm.worklight.config.ant.appserver.AppServerTask.getBackupFileNextId(AppServerTask.java:6358)
 at com.ibm.worklight.config.ant.appserver.AdminAppServerTask.makeTomcatJMXRMIEnvScript(AdminAppServerTask.java:1029)
 at com.ibm.worklight.config.ant.appserver.AdminAppServerTask.buildAndProcessItems(AdminAppServerTask.java:1142)
 at com.ibm.worklight.config.ant.appserver.AppServerTask.setupBuildAndProcessItems(AppServerTask.java:3064)
 at com.ibm.worklight.config.ant.appserver.AppServerTask.doExecute(AppServerTask.java:307)
 at com.ibm.worklight.config.ant.appserver.InstallWorklightAdminTask.execute(InstallWorklightAdminTask.java:43)
 at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:292)
 at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 at java.lang.reflect.Method.invoke(Method.java:498)
 at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
 at org.apache.tools.ant.Task.perform(Task.java:348)
 at org.apache.tools.ant.Target.execute(Target.java:435)
 at org.apache.tools.ant.Target.performTasks(Target.java:456)
 at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1393)
 at org.apache.tools.ant.Project.executeTarget(Project.java:1364)
 at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
 at org.apache.tools.ant.Project.executeTargets(Project.java:1248)
 at org.apache.tools.ant.Main.runBuild(Main.java:851)
 at org.apache.tools.ant.Main.startAnt(Main.java:235)
 at org.apache.tools.ant.launch.Launcher.run(Launcher.java:280)
 at org.apache.tools.ant.launch.Launcher.main(Launcher.java:109)

Total time: 1 second    

Thank you in advance.

The problem was with Tomcat base dir(/var/lib/tomcat7) which doesn't have bin dir and worklight was searching for that. once we repaired tomcat7 installation it worked.

thanks for the support.