While switching SFC Nitrogen over to Karaf4 (https://git.opendaylight.org/gerrit/#/c/58236), I get the below exceptions in these modules:

Blueprint
OpenflowPlugin
OVSDB

2017-06-01 19:08:12,259 | ERROR | rint Extender: 3 | Futures$CombinedFuture | 70 - com.google.guava - 18.0.0 | input future failed.
java.lang.NullPointerException
at org.opendaylight.openflowjava.protocol.impl.core.SwitchConnectionProviderImpl.createAndConfigureServer(SwitchConnectionProviderImpl.java:145)
at org.opendaylight.openflowjava.protocol.impl.core.SwitchConnectionProviderImpl.startup(SwitchConnectionProviderImpl.java:112)
at Proxyfb9788b2_4f93_4b0b_ae36_2782ee5d5246.startup(Unknown Source)
at Proxy1afd4363_9565_4d97_8bb4_d77bdd0a05f7.startup(Unknown Source)
at org.opendaylight.openflowplugin.impl.OpenFlowPluginProviderImpl.lambda$startSwitchConnections$0(OpenFlowPluginProviderImpl.java:150)
at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)[:1.8.0_121]
at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1374)[:1.8.0_121]
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)[:1.8.0_121]
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)[:1.8.0_121]
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)[:1.8.0_121]
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)[:1.8.0_121]
at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)[:1.8.0_121]
at org.opendaylight.openflowplugin.impl.OpenFlowPluginProviderImpl.startSwitchConnections(OpenFlowPluginProviderImpl.java:151)
at org.opendaylight.openflowplugin.impl.OpenFlowPluginProviderImpl.initialize(OpenFlowPluginProviderImpl.java:232)
at org.opendaylight.openflowplugin.impl.OpenFlowPluginProviderFactoryImpl.newInstance(OpenFlowPluginProviderFactoryImpl.java:106)
at Proxy650ae58a_73fb_4bba_9280_96323ba7be9a.newInstance(Unknown Source)
at Proxy335da150_f5cb_4de8_8aed_eda6fe18de98.newInstance(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)[:1.8.0_121]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)[:1.8.0_121]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)[:1.8.0_121]
at java.lang.reflect.Method.invoke(Method.java:498)[:1.8.0_121]
at org.apache.aries.blueprint.utils.ReflectionUtils.invoke(ReflectionUtils.java:299)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BeanRecipe.invoke(BeanRecipe.java:980)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BeanRecipe.getInstanceFromFactory(BeanRecipe.java:295)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BeanRecipe.getInstance(BeanRecipe.java:278)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BeanRecipe.internalCreate2(BeanRecipe.java:830)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BeanRecipe.internalCreate(BeanRecipe.java:811)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.di.AbstractRecipe$1.call(AbstractRecipe.java:79)[12:org.apache.aries.blueprint.core:1.7.1]
at java.util.concurrent.FutureTask.run(FutureTask.java:266)[:1.8.0_121]
at org.apache.aries.blueprint.di.AbstractRecipe.create(AbstractRecipe.java:88)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.di.RefRecipe.internalCreate(RefRecipe.java:62)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.di.AbstractRecipe.create(AbstractRecipe.java:106)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.ServiceRecipe.createService(ServiceRecipe.java:285)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.ServiceRecipe.internalGetService(ServiceRecipe.java:252)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.ServiceRecipe.internalCreate(ServiceRecipe.java:149)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.di.AbstractRecipe$1.call(AbstractRecipe.java:79)[12:org.apache.aries.blueprint.core:1.7.1]
at java.util.concurrent.FutureTask.run(FutureTask.java:266)[:1.8.0_121]
at org.apache.aries.blueprint.di.AbstractRecipe.create(AbstractRecipe.java:88)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BlueprintRepository.createInstances(BlueprintRepository.java:255)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BlueprintRepository.createAll(BlueprintRepository.java:186)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BlueprintContainerImpl.instantiateEagerComponents(BlueprintContainerImpl.java:724)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BlueprintContainerImpl.doRun(BlueprintContainerImpl.java:411)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BlueprintContainerImpl.run(BlueprintContainerImpl.java:276)[12:org.apache.aries.blueprint.core:1.7.1]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)[:1.8.0_121]
at java.util.concurrent.FutureTask.run(FutureTask.java:266)[:1.8.0_121]
at org.apache.aries.blueprint.container.ExecutorServiceWrapper.run(ExecutorServiceWrapper.java:106)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.utils.threading.impl.DiscardableRunnable.run(DiscardableRunnable.java:48)[12:org.apache.aries.blueprint.core:1.7.1]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)[:1.8.0_121]
at java.util.concurrent.FutureTask.run(FutureTask.java:266)[:1.8.0_121]
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)[:1.8.0_121]
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)[:1.8.0_121]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)[:1.8.0_121]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)[:1.8.0_121]
at java.lang.Thread.run(Thread.java:745)[:1.8.0_121]

2017-06-01 19:08:12,282 | WARN | rint Extender: 3 | OpenFlowPluginProviderImpl | 297 - org.opendaylight.openflowplugin.impl - 0.5.0.SNAPSHOT | Some switchConnectionProviders failed to start.
java.lang.NullPointerException
at org.opendaylight.openflowjava.protocol.impl.core.SwitchConnectionProviderImpl.createAndConfigureServer(SwitchConnectionProviderImpl.java:145)
at org.opendaylight.openflowjava.protocol.impl.core.SwitchConnectionProviderImpl.startup(SwitchConnectionProviderImpl.java:112)
at Proxyfb9788b2_4f93_4b0b_ae36_2782ee5d5246.startup(Unknown Source)
at Proxy1afd4363_9565_4d97_8bb4_d77bdd0a05f7.startup(Unknown Source)
at org.opendaylight.openflowplugin.impl.OpenFlowPluginProviderImpl.lambda$startSwitchConnections$0(OpenFlowPluginProviderImpl.java:150)
at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)[:1.8.0_121]
at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1374)[:1.8.0_121]
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)[:1.8.0_121]
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)[:1.8.0_121]
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)[:1.8.0_121]
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)[:1.8.0_121]
at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)[:1.8.0_121]
at org.opendaylight.openflowplugin.impl.OpenFlowPluginProviderImpl.startSwitchConnections(OpenFlowPluginProviderImpl.java:151)
at org.opendaylight.openflowplugin.impl.OpenFlowPluginProviderImpl.initialize(OpenFlowPluginProviderImpl.java:232)
at org.opendaylight.openflowplugin.impl.OpenFlowPluginProviderFactoryImpl.newInstance(OpenFlowPluginProviderFactoryImpl.java:106)
at Proxy650ae58a_73fb_4bba_9280_96323ba7be9a.newInstance(Unknown Source)
at Proxy335da150_f5cb_4de8_8aed_eda6fe18de98.newInstance(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)[:1.8.0_121]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)[:1.8.0_121]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)[:1.8.0_121]
at java.lang.reflect.Method.invoke(Method.java:498)[:1.8.0_121]
at org.apache.aries.blueprint.utils.ReflectionUtils.invoke(ReflectionUtils.java:299)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BeanRecipe.invoke(BeanRecipe.java:980)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BeanRecipe.getInstanceFromFactory(BeanRecipe.java:295)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BeanRecipe.getInstance(BeanRecipe.java:278)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BeanRecipe.internalCreate2(BeanRecipe.java:830)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BeanRecipe.internalCreate(BeanRecipe.java:811)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.di.AbstractRecipe$1.call(AbstractRecipe.java:79)[12:org.apache.aries.blueprint.core:1.7.1]
at java.util.concurrent.FutureTask.run(FutureTask.java:266)[:1.8.0_121]
at org.apache.aries.blueprint.di.AbstractRecipe.create(AbstractRecipe.java:88)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.di.RefRecipe.internalCreate(RefRecipe.java:62)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.di.AbstractRecipe.create(AbstractRecipe.java:106)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.ServiceRecipe.createService(ServiceRecipe.java:285)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.ServiceRecipe.internalGetService(ServiceRecipe.java:252)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.ServiceRecipe.internalCreate(ServiceRecipe.java:149)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.di.AbstractRecipe$1.call(AbstractRecipe.java:79)[12:org.apache.aries.blueprint.core:1.7.1]
at java.util.concurrent.FutureTask.run(FutureTask.java:266)[:1.8.0_121]
at org.apache.aries.blueprint.di.AbstractRecipe.create(AbstractRecipe.java:88)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BlueprintRepository.createInstances(BlueprintRepository.java:255)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BlueprintRepository.createAll(BlueprintRepository.java:186)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BlueprintContainerImpl.instantiateEagerComponents(BlueprintContainerImpl.java:724)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BlueprintContainerImpl.doRun(BlueprintContainerImpl.java:411)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.BlueprintContainerImpl.run(BlueprintContainerImpl.java:276)[12:org.apache.aries.blueprint.core:1.7.1]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)[:1.8.0_121]
at java.util.concurrent.FutureTask.run(FutureTask.java:266)[:1.8.0_121]
at org.apache.aries.blueprint.container.ExecutorServiceWrapper.run(ExecutorServiceWrapper.java:106)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.utils.threading.impl.DiscardableRunnable.run(DiscardableRunnable.java:48)[12:org.apache.aries.blueprint.core:1.7.1]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)[:1.8.0_121]
at java.util.concurrent.FutureTask.run(FutureTask.java:266)[:1.8.0_121]
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)[:1.8.0_121]
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)[:1.8.0_121]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)[:1.8.0_121]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)[:1.8.0_121]
at java.lang.Thread.run(Thread.java:745)[:1.8.0_121]

2017-06-01 19:13:58,232 | INFO | DBConnNotifSer-1 | ServiceRecipe | 12 - org.apache.aries.blueprint.core - 1.7.1 | Unable to create a proxy object for the service .component-1 defined in bundle org.opendaylight.controller.sal-binding-broker-impl/1.6.0.SNAPSHOT with id. Returning the original object instead.
org.apache.aries.proxy.UnableToProxyException: java.lang.ClassFormatError: Duplicate interface name in class file Proxy6e855a6b_461a_4e31_8357_dde357a7212d
at org.apache.aries.proxy.impl.interfaces.ProxyClassLoader.createProxyClass(ProxyClassLoader.java:165)
at org.apache.aries.proxy.impl.interfaces.InterfaceProxyGenerator.getProxyInstance(InterfaceProxyGenerator.java:97)
at org.apache.aries.proxy.impl.AsmProxyManager.createNewProxy(AsmProxyManager.java:80)
at org.apache.aries.proxy.impl.AbstractProxyManager.createDelegatingInterceptingProxy(AbstractProxyManager.java:75)
at org.apache.aries.proxy.impl.AbstractProxyManager.createInterceptingProxy(AbstractProxyManager.java:53)
at org.apache.aries.blueprint.container.ServiceRecipe$TriggerServiceFactory.getService(ServiceRecipe.java:569)[12:org.apache.aries.blueprint.core:1.7.1]
at org.eclipse.osgi.internal.serviceregistry.ServiceFactoryUse$1.run(ServiceFactoryUse.java:212)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at java.security.AccessController.doPrivileged(Native Method)[:1.8.0_121]
at org.eclipse.osgi.internal.serviceregistry.ServiceFactoryUse.factoryGetService(ServiceFactoryUse.java:210)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.serviceregistry.ServiceFactoryUse.getService(ServiceFactoryUse.java:111)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.serviceregistry.ServiceConsumer$2.getService(ServiceConsumer.java:45)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.serviceregistry.ServiceRegistrationImpl.getService(ServiceRegistrationImpl.java:496)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.getService(ServiceRegistry.java:461)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.framework.BundleContextImpl.getService(BundleContextImpl.java:619)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.apache.aries.blueprint.container.AbstractServiceReferenceRecipe.getServiceSecurely(AbstractServiceReferenceRecipe.java:235)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.ReferenceRecipe.getService(ReferenceRecipe.java:246)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.ReferenceRecipe.access$000(ReferenceRecipe.java:56)[12:org.apache.aries.blueprint.core:1.7.1]
at org.apache.aries.blueprint.container.ReferenceRecipe$ServiceDispatcher.call(ReferenceRecipe.java:306)[12:org.apache.aries.blueprint.core:1.7.1]
at Proxy1b555e87_bde0_4dff_b35e_897952a689f6.fromYangInstanceIdentifier(Unknown Source)
at org.opendaylight.ovsdb.southbound.InstanceIdentifierCodec.bindingDeserializer(InstanceIdentifierCodec.java:74)[308:org.opendaylight.ovsdb.southbound-impl:1.5.0.SNAPSHOT]
at org.opendaylight.ovsdb.southbound.InstanceIdentifierCodec.bindingDeserializerOrNull(InstanceIdentifierCodec.java:83)[308:org.opendaylight.ovsdb.southbound-impl:1.5.0.SNAPSHOT]
at org.opendaylight.ovsdb.southbound.SouthboundMapper.getInstanceIdentifier(SouthboundMapper.java:513)[308:org.opendaylight.ovsdb.southbound-impl:1.5.0.SNAPSHOT]
at org.opendaylight.ovsdb.southbound.OvsdbConnectionManager.getEntityFromConnectionInstance(OvsdbConnectionManager.java:513)[308:org.opendaylight.ovsdb.southbound-impl:1.5.0.SNAPSHOT]
at org.opendaylight.ovsdb.southbound.OvsdbConnectionManager.registerEntityForOwnership(OvsdbConnectionManager.java:531)[308:org.opendaylight.ovsdb.southbound-impl:1.5.0.SNAPSHOT]
at org.opendaylight.ovsdb.southbound.OvsdbConnectionManager.connected(OvsdbConnectionManager.java:115)[308:org.opendaylight.ovsdb.southbound-impl:1.5.0.SNAPSHOT]
at org.opendaylight.ovsdb.lib.impl.OvsdbConnectionService.lambda$notifyListenerForPassiveConnection$4(OvsdbConnectionService.java:527)[304:org.opendaylight.ovsdb.library:1.5.0.SNAPSHOT]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)[:1.8.0_121]
at java.util.concurrent.FutureTask.run(FutureTask.java:266)[:1.8.0_121]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)[:1.8.0_121]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)[:1.8.0_121]
at java.lang.Thread.run(Thread.java:745)[:1.8.0_121]
Caused by: java.lang.ClassFormatError: Duplicate interface name in class file Proxy6e855a6b_461a_4e31_8357_dde357a7212d
at java.lang.ClassLoader.defineClass1(Native Method)[:1.8.0_121]
at java.lang.ClassLoader.defineClass(ClassLoader.java:763)[:1.8.0_121]
at org.apache.aries.proxy.impl.interfaces.ProxyClassLoader.createProxyClass(ProxyClassLoader.java:157)
... 30 more