Steps to reproduce:
1) Create a page with Activities portlet
2) Go to Admin Sites: D&M
3) Upload a document
4) Return to Activities page: a new activity has been added
5) Click the link "Go to folder" in Activities portlet
Actual behaviour: This error is shown on console (12:08:43,780 ERROR [http-bio-9082-exec-21][PortletRequestProcessor:466] Forward does not exist), and portal redirects to the NOT FOUND page.
Expected behaviour: portal should know how to deal with activities without context (its related portlet is not present).
If you deploy D&M Display to the same page, then, portal redirects well to that folder and document.