After installing or updating the Clusters plug-in to version 3.3.1 for iManager 2.75, you get a Status Code 500 error whenever you attempt to manage the cluster from iManager.
This problem can occur if iManager loads a version of the class loader file earlier than /var/opt/novell/iManager/nps/WEB-INF/lib/commons-lang-2.6.jar. iManager uses one class loader for all of its plug-ins. If multiple versions of the class loader file exist in the /var/opt/novell/iManager/nps/WEB-INF/lib directory, iManager loads whichever one comes first alphabetically.
To resolve this problem, you must remove the earlier versions (such as commons-lang.jar or commons-lang-2.4.jar) to ensure that iManager loads the 2.6 or later version of the class loader file, then restart Tomcat.
For more information, see Section 5.7, Installing or Updating the Clusters Plug-in for iManager.
This problem has been resolved in the Cluster plug-in for iManager 2.7.6 and later.