When using the tomcat manager to shut down the workbench application, undeploy it, and redeploy, an error appears when trying to access the workbench.
trace:
At first glance, it looks as if the workbench does not properly shut down the repository it uses for storing queries. Possible fix is a runtime shutdownhook, or switching to the new RepositoryProvider class (which takes care of shutting down cleanly for you).
Tomcat 7.0.32 (linux x64)