ValueError("Invalid value") in

After upgrading to Plotly 5 (either 5.1.0 or 5.2.2), I am seeing the error (given below) for various plots, at random. The issue goes away if Plotly is downgraded to 4.14.3.

File "plotly/", line 3952, in _index_is
raise ValueError("Invalid value")

Unfortunately, I do not have a simple reproducible example to open an issue, but here is the description of the problem.

I have a Dash app that plots several graphs. When the Dash app starts, some plots do not get displayed, and I see the error. This only occurs on the initial startup of the app. When the webpage is refreshed, the error does not re-appear, and all plots get displayed without errors.

If I downgrade to Plotly 4.14.3, the issue goes away entirely.

Any ideas what might be causing this?

I am using plotly (online) in a Flask App running with mod_wsgi on an Apache server and I get exactly the same error, randomly also with the latest Plotly version (5.3.1).

Downgrading to 4.14.3 does not help.

So far I can judge, the error also only seems to appear after a server restart. The error also appears for the first plotly graph I try to plot on the webpage (I am plotting several Plotly plots on the page).

I am encountering this issue as well while using Plotly (5.3.1) with Dash (2.0.0). I checked all the data points that I supply to the graph, and they are all float values, i.e. should all be valid. So I have no clue how to debug this other than joining the above users.

There are other reports of this issue:

If you could provide some runnable code for us to look at, it would go a long way towards finding and fixing this issue! :slight_smile:

I think I have a more or less reproducible example. Please see ValueError(“Invalid value”) in · Issue #3441 · plotly/ · GitHub

I might have found a hack, let me know if it’s working for you :slight_smile:

1 Like

Hehe, sneaky! I am sure it will work, but I will only be able to try it in a few days. And I also do not want to hinge me upgrading Plotly on this sort of a hack. I am hoping it will be addressed properly.

I have updated the GitHub issue though with more links to this forum.

Well, I have finally made the decision to migrate to Dash 2.0 and Plotly 5.5.0, and therefore had to implement the hack with try on every graph (as was suggested by @LeoWY), and it worked well.

fig = …
except ValueError::
fig = …

@nicolaskruchten were you able to reproduce the issue by following the example I provided here ValueError(“Invalid value”) in · Issue #3441 · plotly/ · GitHub ?

Hey guys,

I’ve ran into the same problem. The error only happens on initialization, then everything is fine. I’ve quaduple checked my datatypes and they should be valid. One odd thing is I have 2 scatter plots using px.scatter and the error would bounce between the two locations in the code randomly without changing anything.", line 3952, in _index_is
        raise ValueError("Invalid value")

The try/except hack fixes it, but I’m not stoked on that solution.
A solution on github works as well, but only adds to the puzzle:

Here are my dash/plotly versions.
dash 2.7.1
dash-bootstrap-components 1.3.0
dash-core-components 2.0.0
dash-html-components 2.0.0
dash-table 5.0.0
plotly 5.12.0

Indeed, the solution on github worked for me as well. I have a added a comment there about my experience. I feel like it is more of a Dash issue than Plotly. And we are at Dash 2.9.2 right now.