Ipywidgets: Notebook validation failed

[renzocom]

I am using jupyter 1.0.0 and ipywidgets 6.0.0 on Python3 and when I try to save my notebook after calling the display() function from IPython.display I get the following message:

Notebook validation failed: {'model_id': '211cc089c9134af79f0a8ccff7244ae8'} is not valid under any of the given schemas:
{
"model_id": "211cc089c9134af79f0a8ccff7244ae8"
}

Example code that gives the error:
from ipywidgets import FloatProgress
from IPython.display import display
a = FloatProgress(value=7.5,min=0,max=10.0)
display(a)
If I remove the call display(a) and save the file it raises no error.

[SylvainCorlay]

This is a bug that occurs with nbformat < 4.2. If you update nbformat, this should go away.

[renzocom]

Thanks!

[aviogit]

I have nbformat at 5.0.3 and I have this problem... any ideas? Downgrade?

Name: nbformat
Version: 5.0.3
Summary: The Jupyter Notebook format
Home-page: http://jupyter.org

[ivarzap]

Same issue, with nbformat 5.0.4.
Happens when using widgets, like ipyaggrid.

[jasongrout]

Can you post a set of instructions, starting from a clean environment, to reproduce the error with nbformat 5.0.x?

[ivarzap]

I cannot reproduce the error in a clean environment with just ipyaggrid. On the other hand, the behavior is somehow erratic: I have several Notebooks with ipyaggrid working well too.

Those that don't, when opening (if a cell contains the output of a ipyaggrid on save), show the error:

The save operation succeeded, but the notebook does not appear to be valid. The validation error was:

Notebook validation failed: {'model_id': '3f7b24eb3f534f5cb94e5fa15c48d53f', 'version_major': 2, 'version_minor': 0} is not valid under any of the given schemas:
{
"model_id": "3f7b24eb3f534f5cb94e5fa15c48d53f",
"version_major": 2,
"version_minor": 0
}

If I clear the cell's current output, the error disappears.

The server shows the message:

Notebook JSON is invalid: {'version_major': 2, 'version_minor': 0, 'model_id': 'b38fd3f12760491a9b90a5d233f85e6a'} is not valid under any of the given schemas

Failed validating 'oneOf' in display_data['properties']['data']['patternProperties']['^(?!application/json$)[a-zA-Z0-9]+/[a-zA-Z0-9\\-\\+\\.]+$']:

On instance['cells'][11]['outputs'][0]['data']['application/vnd.jupyter.widget-view+json']:
{'model_id': 'b38fd3f12760491a9b90a5d233f85e6a',
 'version_major': 2,
 'version_minor': 0}

How can I reproduce the error?

[ivarzap]

I found a solution to my problem:

From https://github.com/jupyter/nbformat/issues/161#issuecomment-574530127, by updating manually the "nb_format_minor": 1 to "nb_format_minor": 4 the problem disappears.

[aviogit]

The problem disappeared for me as well. My jobs have been killed during the weekend (both jupyter notebook and its kernels) and now, reloading the notebook, everything is fine.