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.
PC-BSD® Bug Reporting/9.2
(Sorry for the inconvenience)
Beginning with PC-BSD® 9.2, a bug reporting tool is available in Control Panel. This tool can also be launched by typing pc-bugreport from the command line. The initial screen for this tool is shown in Figure 8.20a.
Figure 8.20a: PC-BSD® Bug Reporting Utility