dash.exceptions.DependencyException ..... dcc/async-plotlyjs.js

Hi guys,
I have a dash site deployed via render and am intermittently seeing the below error on my server log. What is both good and bad is that I haven’t had any user reports about it, so I can’t tell if it is actually affecting the use of my site. I haven’t been able to replicate it on my side. I am on Python 3.11 and the latest versions of dash, dcc, dbc, plotly, flask and gunicorn.

I found a similar error in the below topic (although it is about DAQ), I have tried the suggested fix of eager_loading=True but I still see the error.

I wondered if anyone might know what this error means in practise and what could be causing it?
Thank you!

Hello @Pippo,

If everything is working when you are testing, then I think you may be running into requests while the server is spinning up and is in an incomplete state.

I notice errors like this locally when I am using a flask server and hot reload. When I refresh too soon on the page I am adjusting, it will come up like this. For me, the page doesnt load quite right.

Since you are using render, if you are using a version that only spins up when it is requested, this could very well be the issue that you are running into as well.

Hi and thanks for the reply. I’m on the paid Render which I believe is permanently on, and I’m seeing the errors a long time after deploying or loading the server, so I don’t think it is to do with spinning up. It seems to occur seemingly randomly (I’ve seen it in the logs around the time of different user agents using the site) in the middle of what looks like normal operations of the site :thinking:

Ok, then what you could be encountering an error in your code and the server is actually crashing and spinning up again. XD