Sorry for the inconvenience. Known Navigation header breakage, its being "rebuilt."
There may be other unforeseen breakage primarily in the handbook portion of the wiki.
The Table Of Contents section of each "PC-BSD® Users Handbook" page may be the best workaround.
These pages may also be orphans (pages that have been superceded and content erased) turned into redirects. Other redirects have no history, never had content, and were created solely to assist with searches or clarity.
This category currently contains no pages or media.