Using BucketTool helper - error in connection to the server, bucket creation, deletion.

BucketTool is not behaving properly to create default bucket and connect to the server.
Error received while running CouchbaseClientTest using the initClient method which is overridden -

java.lang.RuntimeException: Http Error: 401 Reason: Unauthorized Details: No reason given
at com.couchbase.client.ClusterManager.checkError(ClusterManager.java:300)
at com.couchbase.client.ClusterManager.listBuckets(ClusterManager.java:186)
at com.couchbase.client.BucketTool$1.callback(BucketTool.java:73)
at com.couchbase.client.BucketTool.poll(BucketTool.java:108)
at com.couchbase.client.BucketTool.deleteAllBuckets(BucketTool.java:84)
at com.couchbase.client.CouchbaseClientTest.initClient(CouchbaseClientTest.java:60)
at net.spy.memcached.ClientBaseCase.setUp(ClientBaseCase.java:72)
at junit.framework.TestCase.runBare(TestCase.java:132)
at junit.framework.TestResult$1.protect(TestResult.java:110)
at junit.framework.TestResult.runProtected(TestResult.java:128)
at junit.framework.TestResult.run(TestResult.java:113)
at junit.framework.TestCase.run(TestCase.java:124)
at junit.framework.TestSuite.runTest(TestSuite.java:232)
at junit.framework.TestSuite.run(TestSuite.java:227)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:83)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)