The 'Extension host terminated unexpectedly' error in Cursor means the process that runs all extensions has crashed. The most common cause is the Prettier v12+ extension, which has a confirmed incompatibility with Cursor's Extension API. Disable Prettier, restart Cursor, and re-enable extensions one by one to identify the culprit. Also check for memory-intensive extensions.
What does "Extension host terminated unexpectedly" mean in Cursor?
When Cursor shows "Extension host terminated unexpectedly (3 times within the last 5 minutes)," the background process responsible for running all VS Code extensions has crashed repeatedly. Since Cursor is a VS Code fork, it inherits the extension host architecture — but some extensions that work fine in VS Code have specific incompatibilities with Cursor.
When the extension host crashes, all AI features stop working. Tab completion, inline chat, and Composer all depend on the extension host being alive. The error typically appears as a notification in the bottom-right corner, and Cursor may attempt to restart the host automatically, but if it crashes three times within five minutes, it gives up.
A closely related symptom is: "The agent execution provider did not respond within 4 seconds. This may indicate the extension host is not running or is unresponsive." This means the AI agent tried to communicate with the extension host but it was either crashed or hung.
Common causes
The Prettier v12+ extension is
installed, which has a confirmed incompatibility with Cursor's Extension API (prettier/prettier-vscode#3887)
A memory-intensive extension (large language
server, Git extension processing a massive repo) is consuming too much RAM and crashing the host
Multiple extensions with conflicting hooks or
activations create a race condition that crashes the host on startup
A corrupted extension installation has
damaged files that crash the host when the extension loads
The workspace has too many files, causing
file-watching extensions to overwhelm the host process with events
Cursor's own update or the
underlying VS Code engine was updated and broke compatibility with previously working extensions
How to fix "Extension host terminated unexpectedly" in Cursor
The fastest fix is to disable the Prettier extension, which is the most common cause. Open the Extensions panel (Cmd+Shift+X / Ctrl+Shift+X), find Prettier, and click Disable. Restart Cursor. If the crashes stop, Prettier was the culprit. You can switch to Cursor's built-in formatting or use an older Prettier version (v11 or earlier).
If Prettier is not installed or disabling it does not help, use the binary search method to find the problematic extension. Disable all extensions (Extensions panel > ... menu > Disable All Extensions). Restart Cursor. If the crashes stop, re-enable extensions in groups of 5-10, restarting after each group, until you identify which extension causes the crash.
Check Cursor's logs for more detail. On macOS: ~/Library/Application Support/Cursor/logs/. On Windows: %APPDATA%\Cursor\logs\. Look for stack traces or out-of-memory errors around the timestamp of the crash.
If the issue persists with all extensions disabled, the problem may be with Cursor itself. Try clearing the extension host cache: close Cursor, delete the extensions folder (~/Library/Application Support/Cursor/CachedExtensions/ on macOS), and reopen Cursor.
For large projects that overwhelm the extension host, add a .cursorignore file to exclude node_modules, dist, .git, and other large directories from file watching.
Prevention tips
- Disable the Prettier v12+ extension immediately if installed — it has a confirmed Cursor incompatibility and is the number one cause of extension host crashes
- Add a .cursorignore file to exclude node_modules, dist, .git, and build directories from file watching to reduce extension host memory usage
- Use the binary search method (disable all extensions, re-enable in halves) to efficiently identify which extension is causing the crash
- Check Cursor's log files for stack traces and out-of-memory errors to get specific diagnostic information about the crash cause
Still stuck?
Copy one of these prompts to get a personalized, step-by-step explanation.
Cursor keeps showing 'Extension host terminated unexpectedly' and crashing every few minutes. I have about 20 extensions installed. How do I systematically find which extension is causing the crash?
My Cursor editor shows 'Extension host terminated unexpectedly' three times within 5 minutes. Here is my list of installed extensions: [paste list]. Which ones are most likely to cause this issue and how should I troubleshoot?
Frequently asked questions
Why does Cursor show "Extension host terminated unexpectedly" repeatedly?
The most common cause is the Prettier v12+ extension, which has a confirmed incompatibility with Cursor (prettier/prettier-vscode#3887). Other causes include memory-intensive extensions, corrupted installations, and large workspaces overwhelming the extension host. Disable Prettier first, then use the binary search method for other extensions.
Does this error affect Cursor's AI features?
Yes. All AI features (tab completion, inline chat, Composer, Agent) depend on the extension host being active. When the host crashes, AI features stop working entirely. You may also see 'The agent execution provider did not respond within 4 seconds' as a related symptom.
How do I find Cursor's log files to debug the crash?
On macOS: ~/Library/Application Support/Cursor/logs/. On Windows: %APPDATA%\Cursor\logs/. Look for the most recent log files and search for stack traces, 'Extension host' errors, or out-of-memory messages around the time of the crash.
Can I use Prettier with Cursor?
Prettier v11 and earlier work with Cursor. Prettier v12+ has a confirmed incompatibility. Either downgrade to v11, use Cursor's built-in formatter, or wait for either Prettier or Cursor to release a compatibility fix.
Will reinstalling Cursor fix the extension host crash?
Usually not, because the crash is caused by extension incompatibilities that persist across reinstalls. The extensions are stored separately from the Cursor application. You need to disable the problematic extension, not reinstall Cursor.
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