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.
The next section describes all of the EasyPBI settings should you wish to further customize the module before building it. Otherwise, you can skip ahead to the section on building and testing the PBI module.