Cursor Cloud Agent setup fails every time

[scottgigante-hubflow]

Where does the bug appear (feature/product)?

Background Agent (GitHub, Slack, Web, Linear)

Describe the Bug

I’ve tried a dozen times a dozen different ways over a period of about a week to create a cloud agent machine snapshot, but every time I get the error “Failed to open environment window” at the “Validate Setup” step. I even tried it where I do literally nothing to the base image before taking the snapshot and set the install setting to echo. Frustrating enough that I subscribed to Claude.

I’ve tried the suggested fixes in https://forum.cursor.com/t/cannot-configure-cloud-agent-environment/146654/4:

Wait 10-15 minutes and retry setup

I waited a week

Disable VPN/proxy completely

Disabled

Check internet stability: Settings > Network > Run Diagnostics

Ran successfully in seconds

If you have environment.json, delete it and start with basic config

Started with nothing; same error. Started with no file, also tried with a simple template I saw suggested in another similar bug report

{
    "snapshot": "POPULATED_FROM_SETTINGS",
    "install": "pip install -r requirements.txt"
}

Do you use Secrets in Settings → Cloud Agents → Secrets

No

Exact install/start/terminals commands (and how long they usually take locally)

Tried with no commands at all, still fails. Also tried with bash terminal command, pip install install command as above, and many other iterations.

Logs below.

[Status] Creating testing environment… (Snapshot ID: snapshot-20260219-4a2c758e-e18e-4755-96dc-9c38f60fe877, Request ID: 392b8e6e-24df-44a3-a2b9-37ca74a196ee)

No other logs to speak of that I can see.

Steps to Reproduce

• Set up cursor cloud agent
• Start new default environment
• Run on install pip install -r requirements.txt
• Save and build
• Failed to open environment window

Expected Behavior

It should work.

Screenshots / Screen Recordings

Operating System

MacOS

Version Information

Version: 2.3.35 (Universal)
VSCode Version: 1.105.1
Commit: cf8353edc265f5e46b798bfb276861d0bf3bf120
Date: 2026-01-13T07:39:18.564Z (1 mo 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

Yes - Cursor is unusable

[deanrie]

Hey, thanks for the report. This is a known infrastructure issue with the Cloud Agent environment setup, so you’re doing everything right.

A few things to try:

• First, check your Cursor version. You’re on 2.3.35, which is about a month old. Please update to the latest version, there have been a few Cloud Agent fixes since then.

• If that doesn’t help, try using a Dockerfile instead of Manual Snapshot. Docs are here: Cloud Agents | Cursor Docs (see “Manual Setup with Dockerfile”). The idea is to create .cursor/Dockerfile with your base image and system dependencies, then reference it in .cursor/environment.json:

{
  "build": {
    "dockerfile": "Dockerfile",
    "context": "."
  },
  "install": "pip install -r requirements.txt"
}

Then restart Cursor and go to Cursor Settings > Cloud Agents. You should see an option to create a snapshot. A user in a similar thread reported this workaround helped avoid the Manual Snapshot setup failure: Cloud Agent setup fails: “Failed to create testing environment: [invalid_argument] Error”

Let me know how it goes.