Unable to execute or save Jupyter notebook

[frenkcleven]

Issue Type: Bug

Python cells do not execute in Jupyter notebook. It is not possible to save the notebook either. Markdown cells work as expected, I have not tried other languages. Behaviour is identical for local and remote files. Stable build works as expected, Insider build does not.

To reproduce:

1. Create new .ipynb file in folder
2. Open file in Notebook editor
3. Enter arbitrary Python code in cell
4. Run cell, code is not executed (no error, no output)
5. Save file, error is displayed

Error: Failed to save 'test.ipynb': Cannot read property 'Markdown' of undefined.

VS Code version: Code - Insiders 1.54.0-insider (3f0d8a1, 2021-02-17T07:37:50.976Z)
OS version: Darwin x64 20.1.0

System Info

Item	Value
CPUs	Intel(R) Core(TM) i5-8279U CPU @ 2.40GHz (8 x 2400)
GPU Status	2d_canvas: enabled gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on oop_rasterization: enabled opengl: enabled_on protected_video_decode: unavailable_off rasterization: enabled skia_renderer: disabled_off_ok video_decode: enabled webgl: enabled webgl2: enabled
Load (avg)	3, 3, 2
Memory (System)	16.00GB (1.71GB free)
Process Argv	--crash-reporter-id e83ca5e1-86db-4713-87bf-21dc3a62891d
Screen Reader	no
VM	0%

Extensions (7)

Extension	Author (truncated)	Version
vscode-markdownlint	Dav	0.39.0
python	ms-	2021.1.502429796
jupyter	ms-	2020.12.414227025
remote-ssh	ms-	0.64.0
remote-ssh-edit	ms-	0.64.0
material-icon-theme	PKi	4.5.0
material-theme	zhu	3.9.15

(1 theme extensions excluded)

A/B Experiments

vsliv695:30137379
vsins829:30139715
vsliv368cf:30146710
vsreu685:30147344
python383cf:30185419
pythonvspyt617cf:30253240
vspor879:30202332
vspor708:30202333
vspor363:30204092
vstry244:30244315
pythonvsdeb440:30224570
pythonvsded773:30223139
pythonvspyt875:30251590
core-portspanel:30257802
coreuntitledfile:30249963
wslfolderdoccf:30257852

[hkennyv]

Same here, seems related to some breaking changes in the vscode notebooks API (see microsoft/vscode-jupyter#4819). In the meantime, looks like you can downgrade vscode to get it to work for now.

The main issue is being tracked at microsoft/vscode-jupyter#4796 for reference!

[frenkcleven]

Same here, seems related to some breaking changes in the vscode notebooks API (see microsoft/vscode-jupyter#4819). In the meantime, looks like you can downgrade vscode to get it to work for now.

The main issue is being tracked at microsoft/vscode-jupyter#4796 for reference!

Thanks! I was looking for a downgrade binary but was unable to find one. This will do for now.