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.
Make Minor Modifications to a PBI Module/10.1
(Sorry for the inconvenience)
If you have a GitHub account and are logged in, you can contribute minor PBI changes to the here and use a valid email address as you will need to confirm your email address.using a web browser. If you do not have a GitHub account, create one
For example, to add a screenshot for an application, upload the screenshot file to a publicly accessible site, then add the URL to the screenshot in between the quotes of the PBI_SCREENSHOTS="" line in the pbi.conf file for that module. Or, to add a similar application, put the package category and package name in between the PBI_PLUGINS="" line in the pbi.conf file for that module. As an example, refer to the pbi.conf for the www/firefox PBI module. More information about the the available pbi.conf variables can be found in Table 8.1a.
To make the edit, click on the pbi.conf file for the module, click the "Edit" button, make the change, then click the "Commit changes" button. This will issue a "git pull" request which will be reviewed by a developer who will either approve it or contact you if more information about the edit is needed. Once the request is approved, you will receive an email about the approval and the change will appear in AppCafe® when the next package set becomes available. How long that takes depends upon whether the system is set to use the PRODUCTION or EDGE package set.