I've been having trouble getting the recent shiny server to work (using Ubuntu .deb installed with gdebi). I am getting "Not Founds" on situations where a directory with index.Rmd should be served by default. The regular app.R, etc shiny apps work fine. It also works fine being explicit with the URL and including "index.Rmd". But "directory_index on" (the default) doesn't seem to be doing its job entirely.
As a reprex, go get the recent rocker/shiny-verse docker image (which uses the same .deb I do). Run it and you'll see a "Not Found" in the lower right part of the Shiny welcome page, because that iframe sources a directory. Change the index.html to have that URL instead include "index.Rmd" as mentioned by Dirk here:
and you'll see what you're supposed to. Is there some setting I'm missing or some basic thing?