Sorry for the inconvenience. Known Navigation header breakage, its being "rebuilt" but forward nav should be ok now.
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.
Translations:Post Installation Configuration and Installation Troubleshooting/9.2/3/en
If you are dual-booting PC-BSD®, you may need to first add an entry to your boot loader menu. The section on Dual Booting describes how to add a PC-BSD® entry to the GAG, GRUB, and EasyBCD boot loader programs.