The fileURLPrefix is not undocumented, it is listed with everything else https://github.com/OokTech/TW5-Bob/blob/master/Configuration.md
I have not run into any troubles where I had to set the fireURLPrefix before it works, if following the steps as I listed them does not work for you than there is some other problem that we should find and fix. -- You received this message because you are subscribed to the Google Groups "TiddlyWiki" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/tiddlywiki. To view this discussion on the web visit https://groups.google.com/d/msgid/tiddlywiki/373f5cb4-b1b1-431f-9d5d-da3cf62d9c7b%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.

