Topic on Extension talk:VisualEditor

OP resolved his own issue and posted the answer

It appears visual editor does not work with pages that have slashes in their titles. When trying to save edits to these pages, or create a new page with a slash in the title, it results in an "apierror-visualeditor-docserver-http: HTTP 404" error. Watching the parsoid logs, you can see that the request never even makes it to parsoid if this is the case.

I recently updated a wiki which already has a bunch of pages with slashes in the titles which have not posed an issue until now. Is there a workaround or a planned fix for this?

I've just solved this for my wiki. The request isn't even getting as far as Restbase, let alone Parsoid. To fix it you need to have:

AllowEncodedSlashes NoDecode

in your Apache configuration. Without that, Apache rejects any urls with encoded slashes. Also, you need to add the nocanon directive on the end of the ProxyPass line.