Cannot install Blog 9.4 on XWiki 9.7-RC-1

org.xwiki.notifications.NotificationDisplayer
class java.lang.NoClassDefFoundError: org/xwiki/notifications/NotificationDisplayer
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at org.xwiki.classloader.URIClassLoader.defineClass(URIClassLoader.java:238)
    at org.xwiki.classloader.URIClassLoader$1.run(URIClassLoader.java:188)
    at org.xwiki.classloader.URIClassLoader$1.run(URIClassLoader.java:180)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.xwiki.classloader.URIClassLoader.findClass(URIClassLoader.java:179)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at org.xwiki.component.annotation.ComponentAnnotationLoader.register(ComponentAnnotationLoader.java:159)
    at org.xwiki.component.annotation.ComponentAnnotationLoader.initialize(ComponentAnnotationLoader.java:136)
    at org.xwiki.extension.jar.internal.handler.JarExtensionHandler.loadComponents(JarExtensionHandler.java:224)
    at org.xwiki.extension.jar.internal.handler.JarExtensionHandler.install(JarExtensionHandler.java:164)
    at org.xwiki.extension.handler.internal.DefaultExtensionHandlerManager.install(DefaultExtensionHandlerManager.java:85)
    at org.xwiki.extension.job.internal.AbstractExtensionJob.installExtension(AbstractExtensionJob.java:306)
    at org.xwiki.extension.job.internal.AbstractExtensionJob.applyAction(AbstractExtensionJob.java:209)
    at org.xwiki.extension.job.internal.AbstractExtensionJob.applyActions(AbstractExtensionJob.java:157)
    at org.xwiki.extension.job.internal.InstallJob.runInternal(InstallJob.java:154)
    at org.xwiki.job.AbstractJob.runInContext(AbstractJob.java:206)
    at org.xwiki.job.AbstractJob.run(AbstractJob.java:189)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: class java.lang.ClassNotFoundException: org.xwiki.notifications.NotificationDisplayer
    at org.xwiki.classloader.URIClassLoader$1.run(URIClassLoader.java:193)
    at org.xwiki.classloader.URIClassLoader$1.run(URIClassLoader.java:180)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.xwiki.classloader.URIClassLoader.findClass(URIClassLoader.java:179)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at org.xwiki.classloader.URIClassLoader.defineClass(URIClassLoader.java:238)
    at org.xwiki.classloader.URIClassLoader$1.run(URIClassLoader.java:188)
    at org.xwiki.classloader.URIClassLoader$1.run(URIClassLoader.java:180)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.xwiki.classloader.URIClassLoader.findClass(URIClassLoader.java:179)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at org.xwiki.component.annotation.ComponentAnnotationLoader.register(ComponentAnnotationLoader.java:159)
    at org.xwiki.component.annotation.ComponentAnnotationLoader.initialize(ComponentAnnotationLoader.java:136)
    at org.xwiki.extension.jar.internal.handler.JarExtensionHandler.loadComponents(JarExtensionHandler.java:224)
    at org.xwiki.extension.jar.internal.handler.JarExtensionHandler.install(JarExtensionHandler.java:164)
    at org.xwiki.extension.handler.internal.DefaultExtensionHandlerManager.install(DefaultExtensionHandlerManager.java:85)
    at org.xwiki.extension.job.internal.AbstractExtensionJob.installExtension(AbstractExtensionJob.java:306)
    at org.xwiki.extension.job.internal.AbstractExtensionJob.applyAction(AbstractExtensionJob.java:209)
    at org.xwiki.extension.job.internal.AbstractExtensionJob.applyActions(AbstractExtensionJob.java:157)
    at org.xwiki.extension.job.internal.InstallJob.runInternal(InstallJob.java:154)
    at org.xwiki.job.AbstractJob.runInContext(AbstractJob.java:206)
    at org.xwiki.job.AbstractJob.run(AbstractJob.java:189)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)