Wso2 Error while deploying carbon application - wso2

Question

I have downloaded Wos2 Developer Studio, downloaded carbon 4.2 and added it as a server in the developer studio. I started carbon and went to the carbon admin console, I added the following features repository
http://dist.wso2.org/p2/carbon/releases/turing/
and installed the Enterprise service bus. I created an ESB Config project and added a Rest API artefact. I deployed it successfully and it worked. However when I remove it using "Add and Remove.." it tells me it has removed it but in fact has not. Hence when I restart the server I get "Error while deploying carbon application" even through nothing is show as deployed on the server. I then can no longer deploy anything including new projects. Selecting the server "Clean" and the "Publish" does not fix the problem?
INFO {org.wso2.carbon.application.deployer.internal.ApplicationManager} - Deploying Carbon Application : getAPI_1.0.0.car...
[2014-07-10 11:48:23,380] ERROR {org.wso2.carbon.application.deployer.CappAxis2Deployer} - Error while deploying carbon application C:\Users\Ashley\Downloads\wso2carbon-4.2.0\wso2carbon-4.2.0\repository\deployment\server\carbonapps\getAPI_1.0.0.car
java.lang.NullPointerException
at java.util.Hashtable.put(Unknown Source)
at org.apache.synapse.deployers.AbstractSynapseArtifactDeployer.deploy(AbstractSynapseArtifactDeployer.java:146)
at org.wso2.carbon.application.deployer.synapse.SynapseAppDeployer.deployArtifacts(SynapseAppDeployer.java:100)
at org.wso2.carbon.application.deployer.internal.ApplicationManager.deployCarbonApp(ApplicationManager.java:251)
at org.wso2.carbon.application.deployer.CappAxis2Deployer.deploy(CappAxis2Deployer.java:71)
at org.apache.axis2.deployment.repository.util.DeploymentFileData.deploy(DeploymentFileData.java:136)
at org.apache.axis2.deployment.DeploymentEngine.doDeploy(DeploymentEngine.java:810)
at org.apache.axis2.deployment.repository.util.WSInfoList.update(WSInfoList.java:144)
at org.apache.axis2.deployment.RepositoryListener.update(RepositoryListener.java:377)
at org.apache.axis2.deployment.RepositoryListener.checkServices(RepositoryListener.java:254)
at org.apache.axis2.deployment.RepositoryListener.startListener(RepositoryListener.java:371)
at org.apache.axis2.deployment.scheduler.SchedulerTask.checkRepository(SchedulerTask.java:59)
at org.apache.axis2.deployment.scheduler.SchedulerTask.run(SchedulerTask.java:67)
at org.wso2.carbon.core.deployment.CarbonDeploymentSchedulerTask.runAxisDeployment(CarbonDeploymentSchedulerTask.java:65)
at org.wso2.carbon.core.deployment.CarbonDeploymentSchedulerTask.run(CarbonDeploymentSchedulerTask.java:110)
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask.runAndReset(Unknown Source)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(Unknown Source)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)