The following seems to appear in SFT:
2020-03-04T14:18:43,720 | ERROR | Framework Event Dispatcher: org.eclipse.osgi.internal.framework.EquinoxEventPublisher@5efa40fe | FrameworkEvent | 0 - org.eclipse.osgi - 3.12.100.v20180210-1608 | FrameworkEvent ERROR java.lang.NoClassDefFoundError: org/apache/karaf/specs/locator/OsgiLocator at org.apache.karaf.specs.activator.Activator.register(Activator.java:124) ~[org.apache.karaf.specs.activator-4.2.8.jar:4.2.8] at org.apache.karaf.specs.activator.Activator.bundleChanged(Activator.java:96) ~[org.apache.karaf.specs.activator-4.2.8.jar:4.2.8] at org.eclipse.osgi.internal.framework.BundleContextImpl.dispatchEvent(BundleContextImpl.java:908) ~[?:?] at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:230) ~[?:?] at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:148) ~[?:?] at org.eclipse.osgi.internal.framework.EquinoxEventPublisher.publishBundleEventPrivileged(EquinoxEventPublisher.java:213) ~[?:?] at org.eclipse.osgi.internal.framework.EquinoxEventPublisher.publishBundleEvent(EquinoxEventPublisher.java:120) ~[?:?] at org.eclipse.osgi.internal.framework.EquinoxEventPublisher.publishBundleEvent(EquinoxEventPublisher.java:112) ~[?:?] at org.eclipse.osgi.internal.framework.EquinoxContainerAdaptor.publishModuleEvent(EquinoxContainerAdaptor.java:168) ~[?:?] at org.eclipse.osgi.container.ModuleContainer.applyDelta(ModuleContainer.java:719) ~[?:?] at org.eclipse.osgi.container.ModuleContainer.resolveAndApply(ModuleContainer.java:511) ~[?:?] at org.eclipse.osgi.container.ModuleContainer.resolve(ModuleContainer.java:457) ~[?:?] at org.eclipse.osgi.container.ModuleContainer.resolve(ModuleContainer.java:447) ~[?:?] at org.eclipse.osgi.container.ModuleContainer$ContainerWiring.resolveBundles(ModuleContainer.java:1313) ~[?:?] at org.apache.karaf.features.internal.service.BundleInstallSupportImpl.resolveBundles(BundleInstallSupportImpl.java:244) ~[?:?] at org.apache.karaf.features.internal.service.FeaturesServiceImpl.resolveBundles(FeaturesServiceImpl.java:1168) ~[?:?] at org.apache.karaf.features.internal.service.Deployer.deploy(Deployer.java:1022) ~[?:?] at org.apache.karaf.features.internal.service.FeaturesServiceImpl.doProvision(FeaturesServiceImpl.java:1062) ~[?:?] at org.apache.karaf.features.internal.service.FeaturesServiceImpl.lambda$doProvisionInThread$13(FeaturesServiceImpl.java:998) ~[?:?] at java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[?:?] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[?:?] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[?:?] at java.lang.Thread.run(Thread.java:834) ~[?:?]