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.
From PC-BSD Wiki
This section demonstrates how to use this utility to convert an existing FreeBSD port into a PC-BSD® PBI. Create PBIs first, as well as refer to that Guide should you have trouble creating a PBI or wish to create a more complex PBI.