Sorry for the inconvenience. Known Navigation header breakage.
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.
If you wish to create a PBI for PC-BSD versions 7.x or 8.x, refer to the instructions in the The PBI Module Builder Guide.
The PBI format for 9.x is different and the PBI Format for 9.0 and Beyond describes the changes. Documentation will be added to the PC-BSD 9 Handbook describing how to build PBI modules in the new format.