Spring Boot Scheduler Illegal access exception tomcat

Question

I have a spring boot war application running on a dedicated tomcat server. I have a scheduled task in that application:
@Scheduled(cron = "0 0 4 15/1 3/10 ?")

When i shutdown the tomcat server (in my Intellij IDEA) i get this stacktrace:

30-Dec-2020 15:01:02.191 INFO [main] org.apache.coyote.AbstractProtocol.stop Stopping ProtocolHandler ["http-nio-8080"]
30-Dec-2020 15:01:02.392 INFO [quartzScheduler_Worker-9] org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading Illegal access: this web application instance has been stopped already. Could not load [ch.qos.logback.core.status.WarnStatus]. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
    java.lang.IllegalStateException: Illegal access: this web application instance has been stopped already. Could not load [ch.qos.logback.core.status.WarnStatus]. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
        at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading(WebappClassLoaderBase.java:1385)
        at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForClassLoading(WebappClassLoaderBase.java:1373)
        at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1226)
        at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1188)
        at ch.qos.logback.classic.LoggerContext.noAppenderDefinedWarning(LoggerContext.java:186)
        at ch.qos.logback.classic.Logger.callAppenders(Logger.java:264)
        at ch.qos.logback.classic.Logger.buildLoggingEventAndAppend(Logger.java:421)
        at ch.qos.logback.classic.Logger.filterAndLog_0_Or3Plus(Logger.java:383)
        at ch.qos.logback.classic.Logger.debug(Logger.java:482)
        at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:612)
Exception in thread "quartzScheduler_Worker-9" java.lang.NoClassDefFoundError: ch/qos/logback/core/status/WarnStatus
    at ch.qos.logback.classic.LoggerContext.noAppenderDefinedWarning(LoggerContext.java:186)
    at ch.qos.logback.classic.Logger.callAppenders(Logger.java:264)
    at ch.qos.logback.classic.Logger.buildLoggingEventAndAppend(Logger.java:421)
    at ch.qos.logback.classic.Logger.filterAndLog_0_Or3Plus(Logger.java:383)
    at ch.qos.logback.classic.Logger.debug(Logger.java:482)
    at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:612)
Caused by: java.lang.ClassNotFoundException: Illegal access: this web application instance has been stopped already. Could not load [ch.qos.logback.core.status.WarnStatus]. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
    at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForClassLoading(WebappClassLoaderBase.java:1375)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1226)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1188)
    ... 6 more
Caused by: java.lang.IllegalStateException: Illegal access: this web application instance has been stopped already. Could not load [ch.qos.logback.core.status.WarnStatus]. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
    at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading(WebappClassLoaderBase.java:1385)
    at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForClassLoading(WebappClassLoaderBase.java:1373)
    ... 8 more
30-Dec-2020 15:01:12.202 WARNING [main] org.apache.tomcat.util.net.Acceptor.stop The acceptor thread [http-nio-8080-Acceptor] did not stop cleanly
30-Dec-2020 15:01:12.202 INFO [main] org.apache.coyote.AbstractProtocol.destroy Destroying ProtocolHandler ["http-nio-8080"]

Is this behaviour intentionally?

EDIT:
As @Andres Sacco rightly asummed, adding this to my pom solved the issue:

<!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-core -->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-core</artifactId>
            <version>1.2.3</version>
        </dependency>

Answer 1

The solution to this problem is to add the library "logback-core" because not exist in your pom file.