java.util.ConcurrentModificationException

ISSUE: 
java.util.ConcurrentModificationException
      at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
      at java.util.HashMap$EntryIterator.next(Unknown Source)
      at java.util.HashMap$EntryIterator.next(Unknown Source)
      at java.util.HashMap.putAllForCreate(Unknown Source)
      at java.util.HashMap.clone(Unknown Source)
      at
org.apache.catalina.loader.WebappClassLoader.clearReferences(WebappClassLoader.java:1621)
      at
org.apache.catalina.loader.WebappClassLoader.stop(WebappClassLoader.java:1524)
      at org.apache.catalina.loader.WebappLoader.stop(WebappLoader.java:707)
      at
org.apache.catalina.core.StandardContext.stop(StandardContext.java:4557)
      at
org.apache.catalina.core.ContainerBase.removeChild(ContainerBase.java:924)
      at
org.apache.catalina.startup.HostConfig.undeployApps(HostConfig.java:1191)
      at org.apache.catalina.startup.HostConfig.stop(HostConfig.java:1162)
      at
org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:313)
      at
org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
      at org.apache.catalina.core.ContainerBase.stop(ContainerBase.java:1086)
      at org.apache.catalina.core.ContainerBase.stop(ContainerBase.java:1098)
      at
org.apache.catalina.core.StandardEngine.stop(StandardEngine.java:448)
      at
org.apache.catalina.core.StandardService.stop(StandardService.java:584)
      at
org.apache.catalina.core.StandardServer.stop(StandardServer.java:744)
      at org.apache.catalina.startup.Catalina.stop(Catalina.java:628)
      at org.apache.catalina.startup.Catalina.start(Catalina.java:603)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
      at java.lang.reflect.Method.invoke(Unknown Source)
      at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)
      at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)

SOLUTION:

Not Available