Jupyter Notebook preview returns AN ERROR OCCURED.

[evgeny-kolonsky]

🏷️ Discussion Type

Bug

💬 Feature/Topic Area

Issues

Body

Any JUPYTER NOTEBOOK .jpynb file preview in any github repo returns AN ERROR OCCURED. The notebooks themselves are healthy. This issue started today, 30/05/2026. Does it work properly at your repositories?

Guidelines

• I have read the above statement and can confirm my post is relevant to the GitHub feature areas Issues and/or Projects.

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[fullstacksam23]

This issue is not limited to a single repository. It affects every .ipynb file I have tried to open on GitHub on chrome.

Example Repository

Repository: https://github.com/fullstacksam23/Data-Preprocessing

Notebook: https://github.com/fullstacksam23/Data-Preprocessing/blob/main/preprocessing.ipynb

• The notebook opens correctly in Jupyter Notebook and VS Code.
• The notebook file is not corrupted.

[peremartra]

🏷️ Discussion Type

Bug

💬 Feature/Topic Area

Issues

Body

Any JUPYTER NOTEBOOK .jpynb file preview in any github repo returns AN ERROR OCCURED. The notebooks themselves are healthy. This issue started today, 30/05/2026. Does it work properly at your repositories?

Guidelines

• I have read the above statement and can confirm my post is relevant to the GitHub feature areas Issues and/or Projects.

It seems it is universal! all repos I teste are suffering the same issue.

[jeffheaton]

I am running into the same issue.

Fails in GitHub preview:
https://github.com/jupyter/notebook/blob/main/docs/source/examples/Notebook/Running%20Code.ipynb

[Anshu-Tech-Arch]

is the issue fixed or not?

[jeffheaton]

not for me

[evgeny-kolonsky]

Still not fixed

[Anshu-Tech-Arch]

I am running into the same issue, is this universal error?

[brianjancarlos]

same issue https://github.com/Team-Kaizen-MMDC/adet/blob/chore/testnewganache/MS1_Smart_Tracking_System_Blockchain_Ledger_Submission_TeamKaizen.ipynb

[evgeny-kolonsky]

Tried under EDGE browser, the result is the same AN ERROR OCCURED