Logged-in needed web page return 404 error page

[tizianopitisci]

Buddypress redirects to error 404 page every time a user tries to access to logged-in needed web page.
Example:
​https://edizioniopen.it/membri/tizianopitisci/messages/
It sould be redirect to a log-in page. In case I was not clear please read this topic on buddypress forum:
​https://buddypress.org/support/topic/error-404-for-non-logged-in-users/
Moderatos agree that It's a buddypress bug.

[slaFFik]

Duplicates #7349.