Persistent "Extension Host Timeout" & Agent Execution Hang

Support Bug Reports
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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Hi everyone,

I am writing to report a critical and persistent issue I am experiencing with the Cursor editor. My extension host continually crashes, and the AI agent times out, which is completely blocking my development workflow.

The Core Error
Here is the specific error trace I am receiving consistently:

Request ID: 5e58a5d5-9f56-4d44-a3bc-8156338cb936
{“error”:“ERROR_EXTENSION_HOST_TIMEOUT”,“details”:{“title”:“Agent Execution Timed Out”,“detail”:“The agent execution provider did not respond in time. This may indicate the extension host is not running or is unresponsive.”}}
ConnectError: [deadline_exceeded]

Additional Symptoms
Before the crash occurs, the AI agent frequently gets stuck in an infinite loop. It spends 2 to 3 hours executing unnecessary commands (such as running echo, monitoring background tasks, and exploring searches) without making actual progress. Eventually, it throws the timeout error and crashes the extension host, triggering the “Extension host terminated unexpectedly 3 times within the last 5 minutes” warning.

Troubleshooting Steps Already Taken
To rule out local environment issues, I have strictly followed these steps, but the issue remains:

Uninstalled Cursor completely.

Deleted all residual local data (C:\Users<user>\AppData\Roaming\Cursor and C:\Users<user>.cursor).

Restarted my PC and performed a clean, fresh installation.

Tested the setup on entirely different computers.

Tested the editor using different Cursor accounts.

Tried launching via the cursor --classic command.

Ran Extension Bisect, but the issue still persists even with extensions disabled.

Advanced Diagnostics
I also tried manually fixing potential missing directory issues in the cursor-socket extension by symlinking out to dist, but it did not resolve the problem:

PowerShell
cd “$env:LOCALAPPDATA\Programs\cursor\resources\app\extensions\cursor-socket”
New-Item -ItemType SymbolicLink -Path “out” -Target “dist”

Finally, I ran the internal Network Diagnostics, and everything passed perfectly. My machine is successfully resolving and connecting to all Cursor APIs (api2.cursor.sh, prod.authentication.cursor.sh, agent.api5.cursor.sh, etc.) with low latency (under 300ms for pings).

Because this issue persists across completely different machines and different user accounts, it appears to be a backend issue or a severe bug with the agent execution provider rather than a local configuration problem.

I need a solution immediately, as I rely on Cursor for my daily development and this is preventing me from getting any work done. I have already reached out to support but wanted to post here to see if anyone else is experiencing this or knows a workaround.

Steps to Reproduce

Open any project or workspace in the Cursor editor.

Open the Composer / AI Agent interface.

Submit a prompt that requires the agent to analyze the codebase or generate a plan (e.g., “Can you plan to add a TODO feature to this V2 design. Also need API and backend for it.”).

Observe the agent’s execution log. It will enter an infinite loop, continuously running basic commands (like echo), monitoring background tasks, and exploring searches without making actual progress on the prompt.

Wait. After continuously hanging, the internal anysphere.cursor-retrieval process fails, and the UI displays the error: “Extension host terminated unexpectedly 3 times within the last 5 minutes.”

The chat window ultimately outputs the [deadline_exceeded] Agent Execution Timed Out error.

Screenshots / Screen Recordings

Capture 2.jpg
Capture 2.jpg383×237 16.9 KB

Operating System

Windows 10/11

Version Information

Version: 3.1.17 (user setup)
VSCode Version: 1.105.1
Commit: fce1e9ab7844f9ea35793da01e634aa7e50bce90
Date: 2026-04-19T19:33:58.189Z
Layout: editor
Build Type: Stable
Release Track: Default
Electron: 39.8.1
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
OS: Windows_NT x64 10.0.19045

For AI issues: which model did you use?

tried every modals. mainly : Opus 4.7, Composer 2

For AI issues: add Request ID with privacy disabled

Request ID: d8375c10-8b66-418d-90ae-55bae64cd305
{“error”:“ERROR_EXTENSION_HOST_TIMEOUT”,“details”:{“title”:“Agent Execution Timed Out”,“detail”:“The agent execution provider did not respond in time. This may indicate the extension host is not running or is unresponsive.”,“isRetryable”:false,“shouldShowImmediateError”:true,“additionalInfo”:{},“buttons”:[{“label”:“Reload Window”,“reloadWindow”:{}}],“planChoices”:}}
The agent execution provider did not respond in time. This may indicate the extension host is not running or is unresponsive.
Agent Execution Timed Out [deadline_exceeded]
ConnectError: [deadline_exceeded] Agent Execution Timed Out
at rub (vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:38300:25776)
at pgd.waitForProviderRegistration (vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:38300:28797)
at async W1d._waitForPushRequestContextProviderRegistration (vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:41305:4043)
at async W1d.streamFromAgentBackend (vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:41305:7541)
at async W1d.getAgentStreamResponse (vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:41305:18486)
at async N3e.submitChatMaybeAbortCurrent (vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:29033:16809)
at async Object.Va [as onSubmit] (vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:40288:4233)
at async vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:40287:100561

Does this stop you from using Cursor

Yes - Cursor is unusable

5

Hey, this is a known class of bugs with extension host timeout on Windows. We’re tracking the issue, but I can’t share an ETA for a fix yet.

I can see you’ve already tried a lot. One workaround that recently helped in a similar thread Failed to start new Agent chat was that the workspace was untrusted, and in the new layout the trust-folder dialog didn’t show up, silently blocking agent execution.

  1. Fully close Cursor.
  2. Open the project via cursor --classic <path-to-project>.
  3. In classic mode you should see the “Do you trust the authors of this folder?” dialog. Click Trust.
  4. Close Cursor and open it again normally.

This matches a known bug where the Glass layout hides the trust prompt. Since the request IDs aren’t reaching the backend, and network diagnostics pass, the root cause is on the client side, and the trust-folder state is the most common trigger.

If this doesn’t help, please share:

  • Output from Help > Toggle Developer Tools > Console at the moment the agent hangs, look for extension host / cursor-socket errors
  • Whether it reproduces in an empty folder mkdir test && cursor test, then submit a simple prompt
  • Whether there are fresh exthost.log files with errors in %APPDATA%\Cursor\logs\

Separately, the 2 to 3 hour echo loops are model behavior, not extension host behavior. If you can share a link to a specific chat where the model got stuck, I’ll pass it to the team.

7

Hi, thanks for getting back to me and for the context on the Windows extension host bugs.

I tried opening the project via cursor --classic <path-to-project>, but the trust dialog did not appear.

now agents are working. but it’s only running echo commands, waiting and read same files again and again (tried with Composer 2 and Opus 4.7 modals. both same)

image
image589×962 27.9 KB

i tried again and have that same prevous error . :

Request ID: e4c5da87-9a5b-47a5-9a8e-f70fe45ffda6
{“error”:“ERROR_EXTENSION_HOST_TIMEOUT”,“details”:{“title”:“Agent Execution Timed Out”,“detail”:“The agent execution provider did not respond in time. This may indicate the extension host is not running or is unresponsive.”,“isRetryable”:false,“shouldShowImmediateError”:true,“additionalInfo”:{},“buttons”:[{“label”:“Reload Window”,“reloadWindow”:{}}],“planChoices”:}}
The agent execution provider did not respond in time. This may indicate the extension host is not running or is unresponsive.
Agent Execution Timed Out [deadline_exceeded]
ConnectError: [deadline_exceeded] Agent Execution Timed Out
at rub (vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:38300:25776)
at pgd.waitForProviderRegistration (vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:38300:28797)
at async W1d._waitForPushRequestContextProviderRegistration (vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:41305:4043)
at async W1d.streamFromAgentBackend (vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:41305:7541)
at async W1d.getAgentStreamResponse (vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:41305:18486)
at async N3e.submitChatMaybeAbortCurrent (vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:29033:16809)
at async giC.submitMessage (vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:44688:94348)
at async T_C.submitMessage (vscode-file://vscode-app/c:/Users/Induwara%20Uthsara/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:45709:10241)

image
image508×134 3.96 KB

request ID : e4c5da87-9a5b-47a5-9a8e-f70fe45ffda6

8

Thanks for the update and the screenshot. Looks like there are two separate issues here, and it’s best to split them up.

  1. Loop with echo / Waited / Read (screenshot above)

This isn’t an extension host issue. It’s model behavior in Plan mode. Opus 4.7 in Plan mode sometimes gets stuck in this loop and doesn’t finish planning correctly, then falls into repeated reads/echo. This is known, and there’s no ETA for a fix.

What to try as a workaround:

  • Switch from Plan mode to normal Agent mode and run the same prompt again, skip Plan mode.
  • Or switch models, try gpt-5 or composer-2 in Plan mode. This pattern doesn’t reproduce as consistently there right now.
  • If you want to stay on Opus 4.7, make the prompt more direct and avoid “plan” or “analyze the codebase”. For example: “Implement X by modifying files Y and Z”. That tends to trigger Plan mode less often.

If you can share a link to the exact chat where it looped, I can pass it to the team as another report.

  1. ERROR_EXTENSION_HOST_TIMEOUT request e4c5da87-...

This is a known Windows bug, and there’s no timeline for a fix yet. Since the trust dialog didn’t show up with --classic, the workspace is already trusted, so it’s not that.

To move forward, we need logs from the moment the timeout happens:

  1. Help > Toggle Developer Tools > Console. Copy everything around the hang, look for cursor-socket, extensionHost, waitForProviderRegistration.
  2. The latest exthost.log from %APPDATA%\Cursor\logs\<latest folder>\
  3. Does it reproduce in an empty folder: mkdir C:\temp\test && cursor C:\temp\test, open it, send a simple prompt like “write hello world in python”. Do you get the same timeout there?

Item 3 is especially important. If it works fine in an empty folder, the issue is likely tied to that specific workspace like size, .cursorignore contents, or indexing, and that points us in a different direction for debugging.