Symptoms

Some features such as the JIRA issues macro or the Whitelist page do not work.

The following appears in the atlassian-confluence.log:

2014-11-11 11:21:14,829 ERROR [http-bio-12000-exec-35] [atlassian.plugin.servlet.DefaultServletModuleManager] getServlet Unable to create servlet
 -- url: /plugins/servlet/whitelist | userName: user | referer: https://your.confluence.url/admin/console.action
com.atlassian.util.concurrent.LazyReference$InitializationException: java.lang.NoClassDefFoundError: javax/servlet/Servlet

The message may vary but the error should be NoClassDefFoundError javax/servlet/Servlet.

Diagnosis

Dynatrace agent has been set in the JAVA startup options. The option is called agentpath.

Workaround

Remove the agentpath parameter from your JAVA startup options.

Resolution

This is working in Confluence 5.6 and later. Please upgrade you Confluence version if you are facing this problem.