FAILED - Server returned HTTP response code: 403 when trying to use import plugin to import jobs from one Jenkins to another.

It redirects me to the below stack trace.
HTTP Status 500 -

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: java.lang.NullPointerException
org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:603)
org.kohsuke.stapler.Stapler.invoke(Stapler.java:646)
org.kohsuke.stapler.MetaClass$12.dispatch(MetaClass.java:374)
org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:561)
org.kohsuke.stapler.Stapler.invoke(Stapler.java:646)
org.kohsuke.stapler.Stapler.invoke(Stapler.java:477)
org.kohsuke.stapler.Stapler.service(Stapler.java:159)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:94)
hudson.plugins.greenballs.GreenBallFilter.doFilter(GreenBallFilter.java:74)
hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:97)
hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:86)
hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:47)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84)
hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
hudson.security.HudsonFilter.doFilter(HudsonFilter.java:164)
hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:81)
root cause

java.lang.NullPointerException
org.jenkins.ci.plugins.jobimport.JobImportAction.doImport(JobImportAction.java:126)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:616)
org.kohsuke.stapler.Function$InstanceFunction.invoke(Function.java:282)
org.kohsuke.stapler.Function.bindAndInvoke(Function.java:149)
org.kohsuke.stapler.Function.bindAndInvokeAndServeResponse(Function.java:88)
org.kohsuke.stapler.MetaClass$1.doDispatch(MetaClass.java:104)
org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:561)
org.kohsuke.stapler.Stapler.invoke(Stapler.java:646)
org.kohsuke.stapler.MetaClass$12.dispatch(MetaClass.java:374)
org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:561)
org.kohsuke.stapler.Stapler.invoke(Stapler.java:646)
org.kohsuke.stapler.Stapler.invoke(Stapler.java:477)
org.kohsuke.stapler.Stapler.service(Stapler.java:159)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:94)
hudson.plugins.greenballs.GreenBallFilter.doFilter(GreenBallFilter.java:74)
hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:97)
hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:86)
hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:47)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84)
hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
hudson.security.HudsonFilter.doFilter(HudsonFilter.java:164)
hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:81)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.33 logs.

Apache Tomcat/6.0.33