Getting a null pointer exception when i dont use the updateLog parameter in solrConfig.xml

If i disable update log in solr 4.2 then i get the following exception
SEVERE: :java.lang.NullPointerException
at org.apache.solr.cloud.ShardLeaderElectionContext.runLeaderProcess(ElectionContext.java:190)
at org.apache.solr.cloud.LeaderElector.runIamLeaderProcess(LeaderElector.java:156)
at org.apache.solr.cloud.LeaderElector.checkIfIamLeader(LeaderElector.java:100)
at org.apache.solr.cloud.LeaderElector.joinElection(LeaderElector.java:266)
at org.apache.solr.cloud.ZkController.joinElection(ZkController.java:935)
at org.apache.solr.cloud.ZkController.register(ZkController.java:761)
at org.apache.solr.cloud.ZkController.register(ZkController.java:727)
at org.apache.solr.core.CoreContainer.registerInZk(CoreContainer.java:908)
at org.apache.solr.core.CoreContainer.registerCore(CoreContainer.java:892)
at org.apache.solr.core.CoreContainer.register(CoreContainer.java:841)
at org.apache.solr.core.CoreContainer$3.call(CoreContainer.java:638)
at org.apache.solr.core.CoreContainer$3.call(CoreContainer.java:629)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)

Apr 12, 2013 6:39:56 PM org.apache.solr.common.SolrException log
SEVERE: null:org.apache.solr.common.cloud.ZooKeeperException:
at org.apache.solr.core.CoreContainer.registerInZk(CoreContainer.java:931)
at org.apache.solr.core.CoreContainer.registerCore(CoreContainer.java:892)
at org.apache.solr.core.CoreContainer.register(CoreContainer.java:841)
at org.apache.solr.core.CoreContainer$3.call(CoreContainer.java:638)
at org.apache.solr.core.CoreContainer$3.call(CoreContainer.java:629)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.NullPointerException
at org.apache.solr.cloud.ShardLeaderElectionContext.runLeaderProcess(ElectionContext.java:190)
at org.apache.solr.cloud.LeaderElector.runIamLeaderProcess(LeaderElector.java:156)
at org.apache.solr.cloud.LeaderElector.checkIfIamLeader(LeaderElector.java:100)
at org.apache.solr.cloud.LeaderElector.joinElection(LeaderElector.java:266)
at org.apache.solr.cloud.ZkController.joinElection(ZkController.java:935)
at org.apache.solr.cloud.ZkController.register(ZkController.java:761)
at org.apache.solr.cloud.ZkController.register(ZkController.java:727)
at org.apache.solr.core.CoreContainer.registerInZk(CoreContainer.java:908)
... 12 more

and solr fails to start . However if i add updatelog in my solrconfig.xml it starts.