I've just hit a problem configuring a new batch of RUT240, where the latest web UI requires javascript files hosted on an internet CDN. This is a problem for me since usually the RUT240 is the only means of internet access available, so if the mobile connection goes down then I can't get into the router UI any longer.
This just caused me some pain, as I had to factory reset a unit on site. Since the unit no longer had internet access due to the reset, I couldn't reconfigure it to get it back and I ended up in a chicken-and-egg situation.