Error when logging out from business central in B*MS 6.1 with Java Security Manager enabled

Issue

When running BPMS/BRMS with the Java Security Manager enabled, the following ERROR is thrown upon logging out of business-central:

ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[default-host].[/business-central].[jsp]] (http-localhost/127.0.0.1:8080-6) JBWEB000236: Servlet.service() for servlet jsp threw exception: java.lang.SecurityException: attempting to add an object which is not an instance of java.security.Principal to a Subject's Principal Set
    at javax.security.auth.Subject$SecureSet.add(Subject.java:1086) [rt.jar:1.7.0_45]
    at java.util.Collections$SynchronizedCollection.add(Collections.java:1636) [rt.jar:1.7.0_45]
    at org.apache.catalina.connector.Request.setUserPrincipal(Request.java:2059) [jbossweb-7.5.7.Final-redhat-1.jar:7.5.7.Final-redhat-1]
    at org.apache.catalina.authenticator.AuthenticatorBase.unregister(AuthenticatorBase.java:730) [jbossweb-7.5.7.Final-redhat-1.jar:7.5.7.Final-redhat-1]
    at org.apache.catalina.authenticator.AuthenticatorBase.logout(AuthenticatorBase.java:356) [jbossweb-7.5.7.Final-redhat-1.jar:7.5.7.Final-redhat-1]
    at org.apache.catalina.connector.Request.logout(Request.java:3265) [jbossweb-7.5.7.Final-redhat-1.jar:7.5.7.Final-redhat-1]
    at org.apache.catalina.connector.RequestFacade.logout(RequestFacade.java:1019) [jbossweb-7.5.7.Final-redhat-1.jar:7.5.7.Final-redhat-1]
    at org.apache.jsp.logout_jsp._jspService(logout_jsp.java:68)