Dash not displaying at all

I have some code which worked perfectly when I was running on my personal laptop (local host 8050), but unfortunately the exact same code, same versions (of dash libraries etc.) produces a completely blank webpage when I load at work. It’s not a browser issue (in as much as the same blank screen occurs when I load in Chrome or Firefox), but I didn’t think a local hosting of the app requires access to the internet, hence not sure why the corporate firewall could be to blame. Is difficult for me to diagnose as the code (running from a Spyder console or Anaconda prompt) gives no errors, although I did notice it explicitly states all the GET lines when it cycles through loading of the dash components (e.g. GET dash core component, GET dash html component etc.) which I don’t think was the case when I loaded it on my own laptop. I’m asking out of desperation as I can’t see any queries online that displays this kind of behaviour, my local tech guys have no clue and a lot of work is now unusable because I can’t see it in the browser! The source code of the page (after loading) doesn’t seem to display any errors, but this isn’t my forte so I might be missing something there. Equally I have tried to use the two lines suggested by Chris in other questions (app.css.serve_locally = true and scripts.serve_locally = true) but to no avail. I have also copied one of the starter app examples in the dash getting started guide and that displays the same behaviour, so it isn’t anything intrinsically wrong with my code. If anyone has any pointers as to what could be driving this behaviour they would be very gratefully received! Thanks in advance.

it explicitly states all the GET lines

That happens when you try to load the page? That’s a good sign, it means you’re connected to the right url and port. By default we turn that logging off when you’re using debug=True because the console would be flooded by hot reload requests, but when you stop using debug we leave those logs on. But if you can turn debug back on you may see something else in the front-end debugger. Does anything show up in the javascript console?

app.css.serve_locally = true and scripts.serve_locally = true

If you’re using dash 1.0+ those lines are unneeded, local serving is the default.

You said it’s the same dash version in both cases, what version is that?

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Hi Alex, thanks for your response. In (further) desperation I had removed all packages (so all dash, flask-compress, plotly) and reinstalled them first thing this morning…which somehow, miraculously cleared the issue. Of course, being non-scientific I didn’t keep the old versions of the libraries (I am installing offline, after download packages via the Anaconda Cloud), so I can’t tell which packages were upgraded but I can only assume there was a mismatch between some older versions and the reinstall of the latest packages has fixed things (even though I was sure I originally downloaded the latest versions…but perhaps not). Thanks again for the quick response and the extra info regarding debug etc.