Connection Error Today

Support Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Request ID: e6f4849b-b880-4ec4-b4a2-a9c14165fcda
Failed to acquire MessagePort for response channel ‘vscode:createAlwaysLocalSingletonChannelConnectionResult’
RetriableError: Failed to acquire MessagePort for response channel ‘vscode:createAlwaysLocalSingletonChannelConnectionResult’
at EMc (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:12056:26745)
at Fny (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:12057:11929)
at Object.classify (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:12057:16434)
at hAS (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:12057:5824)
at async Oqm.runWithSharedTurnRunner (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:12057:15786)
at async iH.runAgentLoop (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:24486:3041)
at async Lkh.streamFromAgentBackend (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:24505:13862)
at async Lkh.getAgentStreamResponse (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:24505:22888)
at async IRe.submitChatMaybeAbortCurrent (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:12142:2399)
at async du (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:23548:34996)

Steps to Reproduce

I am not sure; I am just gave Cursor IDE a prompt

Expected Behavior

AI Agent should work

Screenshots / Screen Recordings

image (19).png
image (19).png808×1732 23 KB

Operating System

MacOS

Version Information

Version: 3.9.16
VS Code Extension API: 1.105.1
Commit: 042b3c1a4c53f2c3808067f519fbfc67b72cad80
Date: 2026-06-27T06:41:01.941Z
Layout: editor
Build Type: Stable
Release Track: Default
Electron: 40.10.3
Chromium: 144.0.7559.236
Node.js: 24.15.0
V8: 14.4.258.32-electron.0
xterm.js: 6.1.0-beta.256
OS: Darwin arm64 25.5.0

Does this stop you from using Cursor

Yes - Cursor is unusable

5

Hey, thanks for the detailed report with the stack trace and the Request ID, that really helps.

This is a known issue on macOS 26 Tahoe. A local helper process that handles all agent traffic fails to start, and because of that the agent crashes with Failed to acquire MessagePort. This is a bug on our side, there isn’t a reliable workaround yet, and I can’t share an ETA.

A couple things to try that sometimes help temporarily:

  • Fully quit Cursor with Cmd+Q, not just closing the window, then launch it again.
  • Restart your Mac. If the process is stuck at the system level, this can sometimes unblock it.

If the error still happens after that, that’s expected for this bug and we’re tracking it. I’ll post an update in the thread as soon as we have a fix.

8

Alright, thanks

9

I got the same issue today. Fortunately it works after total restart of the cursor.

10

I quit and relaunch cursor and get the same issue

11

@Vek_C, yeah, unfortunately this is expected. A normal quit and relaunch doesn’t always fix this bug, and we don’t have a reliable workaround yet.

The only thing that sometimes helps (unlike just restarting Cursor) is fully rebooting your Mac. If the process is stuck at the system level, a reboot can sometimes unstick it. @hokwanhung, looks like that’s what worked for you.

If the error comes back after rebooting your Mac, that’s also within the expected behavior for this bug. It’s on our side, it’s known and being tracked, but I can’t share an ETA for a fix yet. Once we have an update, we’ll post it in the thread.