# Failed to connect to event stream

**URL:** <https://discourse.jupyter.org/t/failed-to-connect-to-event-stream/527>\
**Category:** Binder\
**Created:** [March 20, 2019, 3:50pm UTC](https://discourse.jupyter.org/t/failed-to-connect-to-event-stream/527 "2019-03-20T15:50:53Z")\
**Posts on this page:** 1\
**Showing post:** 22

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**Author:** ![fomightez](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/fomightez/32/495_2.png) [@fomightez](https://discourse.jupyter.org/u/fomightez)\
**Post date:** [March 16, 2022, 6:33pm UTC](https://discourse.jupyter.org/t/failed-to-connect-to-event-stream/527/22 "2022-03-16T18:33:16Z")

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> [@kaibawong](#):
>
> This is the repo\> [GitHub - kaibawong/EPA](https://github.com/kaibawong/EPA)
> 
> and this is the launch link\>[Binder](https://mybinder.org/v2/gh/kaibawong/EPA/HEAD)

It looks like this one you fixed somewhat since your post.  
It works better unpinned, see [my fork here](https://github.com/fomightez/EPA).  
Or click to launch here:

[![Binder](http://mybinder.org/badge_logo.svg)](http://mybinder.org/v2/gh/fomightez/EPA/HEAD?filepath=appmode_all.ipynb)

When that notebook comes up you can press ‘Appmode’ icon on the toolbar just like before.

You need to specify to open with the classic mode in the URL of your launch badge. MyBinder recently switched to JupyterLab as the default, see [here](https://discourse.jupyter.org/t/mybinder-org-using-jupyterlab-by-default/10715). (I’m not sure why JupyterLab isn’t getting installed without specifying it right now; I think that is a current glitch perhaps as neither the [requirements.txt example](https://github.com/binder-examples/requirements) or the [conda example](https://github.com/binder-examples/conda) show specifying it. The [announcement](https://discourse.jupyter.org/t/mybinder-org-using-jupyterlab-by-default/10715) specifically said Docker installs would need to install JupyterLab. ==\> **UPDATE** : I tracked this down to `nbinteract`. Addition of that under the `pip` section in the `environment.yml` file causes JupyterLab not to be installed as is the typical default. Probably `nbinteract` would do the same if added in `requirements.txt` since I saw JupyterLab installation by the MyBinder system not happen when it was there.)

The big thing I did was move the `environment.yml` file to `binder` directory and unpin everything. Since most of what you had there could be handled by mamba, I also transferred the bulk of it installation over to mamba/conda.  
Actually except for then needing to activate appmode extension separately, you could do the entire install with `requirements.txt`. I did that without separate appmode activation as a test, see [here](https://github.com/fomightez/EPA/tree/9ddcc2b6fb26d04a75b4c493bbbe690d8b02701b). You can launch using that commit [here](https://mybinder.org/v2/gh/fomightez/EPA/9ddcc2b6fb26d04a75b4c493bbbe690d8b02701b?filepath=appmode_all.ipynb). Appmode doesn’t work there as I didn’t do the separate step of activating the extension in a `postBuild` or `start` configuration file.

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