BUG: Waiting for extension host

Support Bug Reports
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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

I cannot run an Agent on any model. It crashes with “Waiting for extension host” error.

Steps to Reproduce

Open Agent tab and run any prompt on any model

Operating System

MacOS

Version Information

Version: 3.0.13 (Universal)
VSCode Version: 1.105.1
Commit: 48a15759f53cd5fc9b5c20936ad7d79847d914b0
Date: 2026-04-07T03:05:17.114Z
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: Darwin arm64 22.6.0

For AI issues: which model did you use?

Any model

For AI issues: add Request ID with privacy disabled

Request ID: a358980b-490b-4b38-a773-04288f8ff35e
{“error”:“ERROR_CUSTOM”,“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”:}}
Agent Execution Timed Out [deadline_exceeded]
ConnectError: [deadline_exceeded] Agent Execution Timed Out
at vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:53345:23460
at async hg_.createExecInstance (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:53345:20015)
at async lqy (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:43738:623141)
at async $4.execute (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:43959:14688)
at async Vhd.execute (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:53345:1749)
at async bK_.execute (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:56367:4966)
at async C0d.buildComposerRequestContext (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:56377:4190)
at async C0d.streamFromAgentBackend (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:56377:6906)
at async C0d.getAgentStreamResponse (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:56377:17161)
at async ZOe.submitChatMaybeAbortCurrent (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:44075:19892)
at async Gl (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:55360:4891)

Does this stop you from using Cursor

Yes - Cursor is unusable

UPD: Switching to the new Agent window unblocked me for now

5

I am also facing same issues. After updating to cursor 3. I can’t also open my jupyter notebooks and whenver I am trying to ask soemthing in c8, it is telling waiting for extension host and then telling me reload windows . I am on Ubuntu 24.04 and cursor3 . Shell → bash

6

Same here.

7

It has been happening for the last 7 days now, no matter what plan, cursor version or model you use.
You can be lucky if either the plan or the agent actually does anything.
@deanrie I do think this is a big issue.

8

Try this. IT worked for me

Clear cache: Delete ~/.config/Cursor/CachedExtensions and

~/.config/Cursor/CachedExtensionVSIXs

Reset user data: Rename ~/.config/Cursor to ~/.config/Cursor_backup

10

It has been helping a lot, but it’s still not back to it’s “fast” standard, that it was having before.

11

Cursor got smarter, when i deleted that folder :slight_smile:
It has been quite bad for a while, i guess the extension cache was one of the reasons.

12

Thank you for reporting @Pavlik_Enemy . This is a known class of issue and we’ve addressed it a piece of it but perhaps not fully resolved it yet. For others who are experiencing this issue can you also check the checklist here that Dean has shared: Waiting for extension host (MacOS) - #5 by deanrie