I'm having trouble supporting jpg fileformat for file upload with ring. Is this not enabled by default? and how do I enable it?

Are you using AJAX form or just post’ing form with input type file? Have you seen note in Ring’s wiki https://github.com/ring-clojure/ring/wiki/File-Uploads ?

im using the google closure iframio.

can you either dump your request on the server and see what are the headers / body or log as cURL from browser's devtools? Maybe, taking a look at those would help you figure out, what the request is and whether you are able to handle it correctly

Does anyone know why I receive this error when clearly the function is in the other namespace?

java.lang.RuntimeException: No such var: ui/app

ui.cljc

(rum/defc app [user]
  …)

(defn home-page [request]
  (layout/render
   "layout.html"
   {:app (rum/render-html (ui/app (:identity request)))}))

It’s as if ui.cljc wasn’t even loading...

But it is since I can access other vars in the namespace

And now it’s randomly working -_-

Ye sometimes you need to evaluate new functions in that namespace happened to me few days ago while debuging webapp xD