When stopping tomcat, the following exception pops up:

INFO: Pausing Coyote HTTP/1.1 on http-8080
Mar 4, 2007 10:14:34 PM org.apache.catalina.core.StandardService stop
INFO: Stopping service Catalina
Mar 4, 2007 10:14:35 PM org.apache.coyote.http11.Http11Protocol destroy
INFO: Stopping Coyote HTTP/1.1 on http-8080
Mar 4, 2007 10:14:35 PM org.apache.catalina.core.AprLifecycleListener lifecycleEvent
INFO: Failed shutdown of Apache Portable Runtime
Mar 4, 2007 10:14:35 PM org.apache.catalina.loader.WebappClassLoader loadClass
INFO: Illegal access: this web application instance has been stopped already.  Could not load org.apache.log4j.spi.VectorWriter.  The eventual following stack trace is caused by an error thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access, and has no functional impact.
java.lang.IllegalStateException
        at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1241)
        at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1201)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
        at org.apache.log4j.spi.LoggingEvent.<init>(LoggingEvent.java:145)
        at org.apache.log4j.Category.forcedLog(Category.java:372)
        at org.apache.log4j.Category.error(Category.java:303)
        at com.ecyrd.jspwiki.util.WikiBackgroundThread.run(WikiBackgroundThread.java:153)
Exception in thread "WatchDog for 'JSPWiki'" java.lang.NoClassDefFoundError: org/apache/log4j/spi/VectorWriter
        at org.apache.log4j.spi.LoggingEvent.<init>(LoggingEvent.java:145)
        at org.apache.log4j.Category.forcedLog(Category.java:372)
        at org.apache.log4j.Category.error(Category.java:303)
        at com.ecyrd.jspwiki.util.WikiBackgroundThread.run(WikiBackgroundThread.java:153)

I've seen this a couple of times as well. It's not dangerous as far as I can tell, just annoying.

-- JanneJalkanen

Is there any way to stop this exception from occuring?

--Paddy, 13-Sep-2007

the same bug, I use JDBC provider. TOMCAT 5.5, java 6.0

--AnonymousCoward, 21-Nov-2007