# Jupyter notebook -- disappearing cells?

**URL:** <https://discourse.julialang.org/t/jupyter-notebook-disappearing-cells/70726>\
**Category:** General Usage\
**Created:** [November 1, 2021, 9:48am UTC](https://discourse.julialang.org/t/jupyter-notebook-disappearing-cells/70726 "2021-11-01T09:48:23Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![BLI](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bli/32/37206_2.png) [@BLI](https://discourse.julialang.org/u/BLI)\
**Post date:** [November 1, 2021, 9:48am UTC](https://discourse.julialang.org/t/jupyter-notebook-disappearing-cells/70726/1 "2021-11-01T09:48:23Z")

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I had a Jupyter notebook running in my browser, and suddenly I was told that there was a problem with connection to the server. It seemed like Julia had crashed…

When I open notebooks after that, some cells don’t show in the browser, but are indicated by horizontal lines:  
 ![image](https://global.discourse-cdn.com/julialang/original/3X/a/b/ab4e9cc046662c7682fd236c835c91a5974d8ce7.png)

Apparently, the code is still there. When I open the notebook in an ASCII editor, I observe that code cells that still are visible, have the following structure:

```julia
"cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [],
   "source": [
    "x0 = [28., 28., 28., 14.,18.,22.]\n",
    "tspan = (0.0,583*60.)\n",
...

```

(_observe_ `"execution_count": 12,`), while cells that are hidden look like:

```julia
"cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Model vs data\n",
    "idx = 1:10:584\n",

```

(_observe_ `"execution_count": null,`).

Questions:

- Is the problem that the execution count has been set to `null`?
- Can I manually change this to some number? Do the `execution_count` number has to be an integer in sequence, starting from the top?

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**Author:** ![Paul\_Soderlind](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/paul_soderlind/32/1753_2.png) [@Paul\_Soderlind](https://discourse.julialang.org/u/Paul_Soderlind)\
**Post date:** [November 1, 2021, 11:01am UTC](https://discourse.julialang.org/t/jupyter-notebook-disappearing-cells/70726/2 "2021-11-01T11:01:32Z")

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is it this ([https://github.com/jupyterlab/jupyterlab/issues/10840#issuecomment-903130229](https://github.com/jupyterlab/jupyterlab/issues/10840#issuecomment-903130229))? If so, upgrade.

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**Author:** ![BLI](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bli/32/37206_2.png) [@BLI](https://discourse.julialang.org/u/BLI)\
**Post date:** [November 1, 2021, 11:08am UTC](https://discourse.julialang.org/t/jupyter-notebook-disappearing-cells/70726/3 "2021-11-01T11:08:40Z")

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I’ll check. I _did_ `Pkg.update()`, but perhaps more is needed.

Yes, I used `jupyterlab()`, and the the notebook opens without problem in `notebook()`.

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**Author:** ![BLI](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bli/32/37206_2.png) [@BLI](https://discourse.julialang.org/u/BLI)\
**Post date:** [November 1, 2021, 12:16pm UTC](https://discourse.julialang.org/t/jupyter-notebook-disappearing-cells/70726/4 "2021-11-01T12:16:30Z")

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OK… I did:

```julia
using Conda
Conda.rm("jupyterlab")

```

and then:

```julia
using IJulia
jupyterlab()

```

leading to a question whether I want to install `jupyterlab`. I answered “yes”.

The problem still persists.

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<div class="post-metadata">

**Author:** ![Paul\_Soderlind](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/paul_soderlind/32/1753_2.png) [@Paul\_Soderlind](https://discourse.julialang.org/u/Paul_Soderlind)\
**Post date:** [November 1, 2021, 12:27pm UTC](https://discourse.julialang.org/t/jupyter-notebook-disappearing-cells/70726/5 "2021-11-01T12:27:40Z")

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sorry, I have no other ideas

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<div class="post-metadata">

**Author:** ![BLI](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bli/32/37206_2.png) [@BLI](https://discourse.julialang.org/u/BLI)\
**Post date:** [November 2, 2021, 10:36am UTC](https://discourse.julialang.org/t/jupyter-notebook-disappearing-cells/70726/6 "2021-11-02T10:36:09Z")

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OK – I removed everything relating to Julia, Conda, Matplotlib, Jupyter, etc., and upgraded to Julia v1.6.3 + reinstalled packages.

Now, it seems like I can open the notebook using `jupyterlab()`… BUT after running for a while, I keep getting the following message:

 ![image](https://global.discourse-cdn.com/julialang/original/3X/0/4/046d261621020707f25328d07a3569519cd33824.png)

I’m on Windows 11, and I have a feeling Microsoft updated Microsoft 365 on my computer yesterday, and possibly browser (chromium) Edge.

- Could a bug in the Julia - Edge interaction have been introduced? [I’ll try to use Firefox as browser – unfortunately, in Windows 11 it is more complicated to change browser…]

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**Author:** ![empet](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/empet/32/221303_2.png) [@empet](https://discourse.julialang.org/u/empet)\
**Post date:** [November 2, 2021, 11:34am UTC](https://discourse.julialang.org/t/jupyter-notebook-disappearing-cells/70726/7 "2021-11-02T11:34:45Z")

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I have been experiencing the same issue for about 3 days. I noticed that whenever I do not accept updates and postpone them for a future time, Windows (10 in my case) generates troubles. After installing updates the issues disappear.

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<div class="post-metadata">

**Author:** ![BLI](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bli/32/37206_2.png) [@BLI](https://discourse.julialang.org/u/BLI)\
**Post date:** [November 2, 2021, 3:07pm UTC](https://discourse.julialang.org/t/jupyter-notebook-disappearing-cells/70726/8 "2021-11-02T15:07:31Z")

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In addition to updating to Windows 11 + possibly an update in Edge/Windows 365 on my computers, I have also been asked to use `Conda` to update `PyPlot`.