Inconsistent: Getting stack trace while logging out of JIRA.

Steps:
1. Logging out of JIRA is throwing stack trace sometime. Not sure of actual reason.
2. Seeing this problem from last 2-3 build.
3. Mostly I am working on Project avatar/JQL during this period.

Result:
1. http://localhost:8080/secure/Logout!default
.jspa [webwork.util.ValueStack] METHOD: "unescapedText", exception:
java.lang.IllegalStateException: getAttribute: Session already invalidated
at org.apache.catalina.session.StandardSession.getAttribute(StandardSession.java:1021)
at org.apache.catalina.session.StandardSessionFacade.getAttribute(StandardSessionFacade.java:110)

2. Full error log is attached

Expected:
1. No error message should be there.