What causes IllegalStateException Invalid BundleContext ?

Issue

• After creating fabric why the following error appears in fuse console:

Error in initialization script: Command not found: shell:if
JBossFuse:karaf@root> io.fabric8.fabric-agent[io.fabric8.agent.DeploymentAgent] : Unable to update agent
java.lang.IllegalStateException: Invalid BundleContext.
    at org.apache.felix.framework.BundleContextImpl.checkValidity(BundleContextImpl.java:517)
    at org.apache.felix.framework.BundleContextImpl.getServiceReference(BundleContextImpl.java:359)
    at io.fabric8.agent.DeploymentAgent.installFeatureConfigs(DeploymentAgent.java:1000)
    at io.fabric8.agent.DeploymentAgent.doUpdate(DeploymentAgent.java:526)
    at io.fabric8.agent.DeploymentAgent$2.run(DeploymentAgent.java:252)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)
io.hawt.hawtio-maven-indexer[io.hawt.maven.indexer.AsyncMavenIndexerFacadeFactory] : Failed to create the MavenIndexerFacade: java.lang.NullPointerException
java.lang.NullPointerException
        at org.apache.lucene.store.Directory.copy(Directory.java:234)
        at org.apache.lucene.store.Directory.copy(Directory.java:277)
        at org.apache.maven.index.context.IndexUtils.copyDirectory(IndexUtils.java:51)
        at org.apache.maven.index.context.DefaultIndexingContext.replace(DefaultIndexingContext.java:571)
        at org.apache.maven.index.updater.DefaultIndexUpdater.loadIndexDirectory(DefaultIndexUpdater.java:218)
        at org.apache.maven.index.updater.DefaultIndexUpdater.access$300(DefaultIndexUpdater.java:76)
        at org.apache.maven.index.updater.DefaultIndexUpdater$LuceneIndexAdaptor.setIndexFile(DefaultIndexUpdaer.java:642)
        at org.apache.maven.index.updater.DefaultIndexUpdater.fetchAndUpdateIndex(DefaultIndexUpdater.java:862)
        at org.apache.maven.index.updater.DefaultIndexUpdater.fetchAndUpdateIndex(DefaultIndexUpdater.java:157)
        at io.hawt.maven.indexer.MavenIndexerFacade.downloadOrUpdateIndices(MavenIndexerFacade.java:171)
        at io.hawt.maven.indexer.MavenIndexerFacade.init(MavenIndexerFacade.java:129)
        at io.hawt.maven.indexer.AsyncMavenIndexerFacadeFactory.createMavenIndexer(AsyncMavenIndexerFacadeFactory.java:134)
        at io.hawt.maven.indexer.AsyncMavenIndexerFacadeFactory$1.run(AsyncMavenIndexerFacadeFactory.java:49)
        at java.util.TimerThread.mainLoop(Timer.java:555)
        at java.util.TimerThread.run(Timer.java:505)