1) Start 6.2 vanilla and login as Admin
2) Place the Page Comments portlet onto the Welcome page
3) Place the Wiki portlet onto the same page
4) In the Wiki portlet, click on All Pages > Add Page
5) Add a comment in the Page Comments portlet and hit "Reply"
Expected: the Page Comments portlet to refresh automatically and the new comment to appear
Result: The Page Comments portlet disappears, the server prints
Since this a Struts related issue, and Page Comments on master is no more a StrutsPortlet, the issue doesn't appear there.