No renderer found for 'text/markdown'

[Jun_Hao_Ho]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Markdown cells in ipynb cannot be rendered

error message: “No renderer found for text/markdown”

Unable to enable the extension

identical to No renderer found for text/markdown

Steps to Reproduce

start cursor for a remote workspace
search for extension using @builtin markdown

Screenshots / Screen Recordings

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

Version: 2.3.30 (Universal)
VSCode Version: 1.105.1
Commit: d1289018cc3fcc395487f65455e31651734308d0
Date: 2026-01-08T05:21:38.211Z (1 day ago)
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Darwin arm64 24.6.0

Does this stop you from using Cursor

No - Cursor works, but with this issue

[deanrie]

Hey, thanks for the report.

This issue is related to how extensions work in a Remote SSH environment. The team has been notified.

For debugging, could you share:

1. Details about your SSH setup: what OS are you connecting to remotely?
2. Does Markdown rendering work in local .ipynb files (without an SSH connection)?
3. Logs from the Developer Tools Console (CMD + Shift + I, Console tab) while you try to open a .ipynb file
4. A list of installed extensions in the remote environment CMD + Shift + X

Temporary workaround: try reconnecting to the SSH host or restart Cursor.

[Jun_Hao_Ho]

As requested

1. Linux (it was working before upgrading to version 2.3)
2. Markdown rendering works on local
3. Console log below:
4. Installed extension in screenshot

workbench.desktop.main.js:16013 An iframe which has both allow-scripts and allow-same-origin for its sandbox attribute can escape its sandboxing.mountTo @ workbench.desktop.main.js:16013_initialize @ workbench.desktop.main.js:8209createWebview @ workbench.desktop.main.js:8209(anonymous) @ workbench.desktop.main.js:8361_resolveWebview @ workbench.desktop.main.js:8361_warmupWithMarkdownRenderer @ workbench.desktop.main.js:8361_attachModel @ workbench.desktop.main.js:8361setModel @ workbench.desktop.main.js:8361setInput @ workbench.desktop.main.js:14080await in setInputdoSetInput @ workbench.desktop.main.js:944doOpenEditor @ workbench.desktop.main.js:944openEditor @ workbench.desktop.main.js:944(anonymous) @ workbench.desktop.main.js:7896doShowEditor @ workbench.desktop.main.js:7896doOpenEditor @ workbench.desktop.main.js:7896openEditor @ workbench.desktop.main.js:7896openEditor @ workbench.desktop.main.js:12742await in openEditor(anonymous) @ workbench.desktop.main.js:7912_deliver @ workbench.desktop.main.js:49fire @ workbench.desktop.main.js:49_open @ workbench.desktop.main.js:459onPointer @ workbench.desktop.main.js:459(anonymous) @ workbench.desktop.main.js:459_deliver @ workbench.desktop.main.js:49fire @ workbench.desktop.main.js:49(anonymous) @ workbench.desktop.main.js:47_deliver @ workbench.desktop.main.js:49fire @ workbench.desktop.main.js:49(anonymous) @ workbench.desktop.main.js:47_deliver @ workbench.desktop.main.js:49fire @ workbench.desktop.main.js:49onViewPointer @ workbench.desktop.main.js:296onViewPointer @ workbench.desktop.main.js:458(anonymous) @ workbench.desktop.main.js:47_deliver @ workbench.desktop.main.js:49fire @ workbench.desktop.main.js:49(anonymous) @ workbench.desktop.main.js:47_deliver @ workbench.desktop.main.js:49fire @ workbench.desktop.main.js:49n @ workbench.desktop.main.js:136index.html?id=b848e1a1-d9dc-4e69-9432-76c927be00fe&origin=1bf23ae6-06f7-4860-882e-312664920c50&swVersion=4&extensionId=&platform=electron&vscode-resource-base-authority=vscode-resource.vscode-cdn.net&parentOrigin=vscode-file%3A%2F%2Fvscode-app&remoteAuthority=ssh-remote%2Bnotebook-personalSandbox&purpose=notebookRenderer:281 Found unexpected service worker controller. Found: vscode-webview://0e6dt34jg9kknisnc52u2td93lfecdag724rnfg6n5m4vo3falae/service-worker.js?v=4&vscode-resource-base-authority=vscode-resource.vscode-cdn.net&id=11fd9c8e-d095-48a1-915e-6def0896148a&remoteAuthority=ssh-remote+notebook-personalSandbox. Expected: service-worker.js?v=4&vscode-resource-base-authority=vscode-resource.vscode-cdn.net&id=b848e1a1-d9dc-4e69-9432-76c927be00fe&remoteAuthority=ssh-remote+notebook-personalSandbox. Waiting for controllerchange.

[deanrie]

Thanks for the info. I can see the issue, it’s a service worker controller mismatch in a Remote SSH environment with Jupyter notebooks.

This is a known regression in version 2.3. A similar issue was reported here: No renderer found for text/markdown, and it was fixed by updating.

I’ll keep you posted as soon as a fix is available.

[ravirahman]

Can you try removing the ~/.cursor-server folder on your remote SSH host, and then reconnect and re-open the notebook?