Hello Emmanuel, I do not know if it is related, but according to your description, probably yes. By putting the ServerUserPreference to null, it works (even behind the proxy), but, the performances to load a complex model (10-20Mb) are seriously degraded. In fact your idea to have the furniture managed with independent files is very efficient and takes advantage of the browser cache. I wonder if you can think of a way (in your next releases) to have the serverUserPreferences to work well behing a proxy, by separating the backend URLs and the frontend-URLs. Maybe it is already the case as the Server class accepts 2 couples of URLs, but I could not figure it out