Created attachment 31414 [details] StackTrace. We currently run an environment with Websphere 7.0 backends ( IBM 1.6 JDK ) and Tomcat 6 front ends ( Oracle 1.6 jdk) and we have just had a case where the backend has thrown an exception which has bubbled up to our web servers, and has been logged with the EnhancedThrowableRender. This has resulted in a java.lang.NoClassDefFoundError from the findClass method of the EnhancedThrowableRender, as this is an Error rather than an Exception this has bypassed the catch Exception block of the doRenderMethod, so rather than defaulting back to the DefaultThrowableRender it has crashed the application. I would have expected that the doRenderMethod should be catching Throwable rather than Exception, or at least the NoClassDefFoundError.