Synchronization Issue while unbinding dynamic injected services

java.lang.NullPointerExceptionjava.lang.NullPointerException at java.util.TreeMap.rotateLeft(TreeMap.java:2224) at java.util.TreeMap.fixAfterDeletion(TreeMap.java:2397) at java.util.TreeMap.deleteEntry(TreeMap.java:2332) at java.util.TreeMap.remove(TreeMap.java:608) at org.apache.felix.scr.impl.inject.field.FieldHandler.updateField(FieldHandler.java:248) at org.apache.felix.scr.impl.inject.field.FieldHandler.access$400(FieldHandler.java:49) at org.apache.felix.scr.impl.inject.field.FieldHandler$Resolved.invoke(FieldHandler.java:422) at org.apache.felix.scr.impl.inject.field.FieldHandler$ReferenceMethodImpl.invoke(FieldHandler.java:492) at org.apache.felix.scr.impl.manager.DependencyManager.invokeUnbindMethod(DependencyManager.java:1927) at org.apache.felix.scr.impl.manager.SingleComponentManager.invokeUnbindMethod(SingleComponentManager.java:458) at org.apache.felix.scr.impl.manager.DependencyManager$MultipleDynamicCustomizer.removedService(DependencyManager.java:382) at org.apache.felix.scr.impl.manager.DependencyManager$MultipleDynamicCustomizer.removedService(DependencyManager.java:294) at org.apache.felix.scr.impl.manager.ServiceTracker$Tracked.customizerRemoved(ServiceTracker.java:1242) at org.apache.felix.scr.impl.manager.ServiceTracker$Tracked.customizerRemoved(ServiceTracker.java:1137) at org.apache.felix.scr.impl.manager.ServiceTracker$AbstractTracked.untrack(ServiceTracker.java:997) at org.apache.felix.scr.impl.manager.ServiceTracker$Tracked.serviceChanged(ServiceTracker.java:1176) at org.apache.felix.scr.impl.BundleComponentActivator$ListenerInfo.serviceChanged(BundleComponentActivator.java:125) at org.apache.felix.framework.EventDispatcher.invokeServiceListenerCallback(EventDispatcher.java:990) at org.apache.felix.framework.EventDispatcher.fireEventImmediately(EventDispatcher.java:838) at org.apache.felix.framework.EventDispatcher.fireServiceEvent(EventDispatcher.java:545) at org.apache.felix.framework.Felix.fireServiceEvent(Felix.java:4833) at org.apache.felix.framework.Felix.access$000(Felix.java:112) at org.apache.felix.framework.Felix$1.serviceChanged(Felix.java:434) at org.apache.felix.framework.ServiceRegistry.unregisterService(ServiceRegistry.java:170) at org.apache.felix.framework.ServiceRegistrationImpl.unregister(ServiceRegistrationImpl.java:145) at org.eclipse.smarthome.core.thing.binding.BaseThingHandlerFactory.unregisterFirmwareUpdateHandler(BaseThingHandlerFactory.java:310) at org.eclipse.smarthome.core.thing.binding.BaseThingHandlerFactory.unregisterHandler(BaseThingHandlerFactory.java:277) at org.eclipse.smarthome.core.thing.internal.ThingManagerImpl.doUnregisterHandler(ThingManagerImpl.java:845) at org.eclipse.smarthome.core.thing.internal.ThingManagerImpl.unregisterHandler(ThingManagerImpl.java:835) at org.eclipse.smarthome.core.thing.internal.ThingManagerImpl.unregisterAndDisposeHandler(ThingManagerImpl.java:916) at org.eclipse.smarthome.core.thing.internal.ThingManagerImpl.thingRemoved(ThingManagerImpl.java:491) at org.eclipse.smarthome.core.thing.internal.ThingRegistryImpl.notifyTrackers(ThingRegistryImpl.java:218) at org.eclipse.smarthome.core.thing.internal.ThingRegistryImpl.notifyListenersAboutRemovedElement(ThingRegistryImpl.java:138) at org.eclipse.smarthome.core.thing.internal.ThingRegistryImpl.notifyListenersAboutRemovedElement(ThingRegistryImpl.java:54) at org.eclipse.smarthome.core.common.registry.AbstractRegistry.removed(AbstractRegistry.java:243) at org.eclipse.smarthome.core.common.registry.AbstractRegistry.removed(AbstractRegistry.java:55) at org.eclipse.smarthome.core.common.registry.AbstractProvider.notifyListeners(AbstractProvider.java:64) at org.eclipse.smarthome.core.common.registry.AbstractProvider.notifyListeners(AbstractProvider.java:80) at org.eclipse.smarthome.core.common.registry.AbstractProvider.notifyListenersAboutRemovedElement(AbstractProvider.java:88) at org.eclipse.smarthome.core.common.registry.AbstractManagedProvider.remove(AbstractManagedProvider.java:104) at org.eclipse.smarthome.core.common.registry.AbstractRegistry.remove(AbstractRegistry.java:342) at org.eclipse.smarthome.core.thing.internal.ThingRegistryImpl.forceRemove(ThingRegistryImpl.java:105) at org.eclipse.smarthome.core.thing.internal.ThingManagerImpl.lambda$notifyRegistryAboutForceRemove$12(ThingManagerImpl.java:1013) at com.qivicon.runtime.executors.impl.ScheduledExecutorServiceImpl$NamedRunnable.run(ScheduledExecutorServiceImpl.java:80) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748)FrameworkEvent error