Complete Guide to Cursor Network Issues: From Proxy Configuration to HTTP/2 Troubleshooting

It’s 1 AM. I’m staring at that spinning circle in the bottom-right corner of Cursor—it’s been going for five minutes. I’ve cursed under my breath a hundred times already. Code halfway done, AI suddenly drops out, showing “Network request failed.” Switch to the browser—YouTube streaming smoothly, ping to Google showing 20ms latency.

Sound familiar?

Even worse was the next day. Corporate network, IT department’s multi-layered proxies, and Cursor just refused to start. Error logs filled with ERR_HTTP2_PROTOCOL_ERROR, ECONNREFUSED, certificate verify failed—I recognize each word individually, but together they make no sense.

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I spent three full days digging through GitHub Issues, Discord channels, and countless “ultimate solution” posts, only to discover: Cursor’s network problems aren’t caused by a single issue, but rather four pitfalls stacked together—proxy, HTTP/2, certificates, and DNS.

This article is my troubleshooting diary. No fluff, just direct troubleshooting steps and solutions. If you’ve also found yourself cursing at your editor in the middle of the night, this can save you 72 hours.

Don’t Rush to Change Configs: Three Steps to Quickly Locate the Problem

When network issues arise, many people immediately start changing proxies, deleting certificates, and reinstalling software. After all that hassle, the problem isn’t solved and the environment is even messier.

My advice: spend 5 minutes confirming what’s actually wrong.

Step 1: Confirm if it’s Cursor’s problem or your network’s problem

Open the terminal and run three commands:

# Test basic network
ping api.openai.com

# Test DNS resolution
nslookup api.openai.com

# Test HTTPS connection
curl -I https://api.openai.com

If ping works but curl fails, it’s almost certainly a proxy or certificate issue. If even ping doesn’t work, the problem is at your network layer, not Cursor.

Step 2: Check Cursor’s error logs

Many people skip this step, but the logs spell it out clearly.

• Windows: %APPDATA%\Cursor\logs\main.log
• macOS: ~/Library/Application Support/Cursor/logs/main.log
• Linux: ~/.config/Cursor/logs/main.log

Open with a text editor and search for ERROR or WARN. Common errors:

• ECONNREFUSED → Proxy misconfigured, or proxy server is down
• ERR_HTTP2_PROTOCOL_ERROR → HTTP/2 protocol incompatibility (the most frustrating one)
• certificate verify failed → SSL certificate issue
• ETIMEDOUT → Timeout, possibly slow DNS or blocked

Step 3: Test if Cursor’s proxy settings are working

Cursor is Electron-based, and its proxy configuration doesn’t use the system proxy—you need to configure it separately. Testing method:

1. Open Cursor settings (Ctrl+, or Cmd+,)
2. Search for proxy
3. Check if http.proxy and https.proxy are empty

If they’re empty, but you have proxy software running locally (Clash, V2Ray, Shadowsocks), then Cursor isn’t using the proxy at all—of course it can’t connect.

Four Ways to Configure Proxy (There’s Always One That Fits)

Proxy issues are the number one culprit in Cursor network failures. But many people don’t know that Cursor supports four different proxy configuration methods, each for completely different scenarios.

Method 1: Fill in proxy address directly in settings (easiest)

Applicable scenario: You have a clear proxy server address (like an HTTP proxy provided by your company)

Steps:

1. Open Cursor settings
2. Search for proxy
3. Fill in http.proxy: http://127.0.0.1:7890 (replace with your proxy address and port)

Pitfalls to watch out for:

• If proxy requires username/password, format is http://username:[email protected]:7890
• HTTPS proxy also needs separate https.proxy configuration, otherwise only HTTP requests go through proxy
• Some proxy software (like Clash) default port is 7890, others (V2Ray) use 10808—don’t mix them up

Method 2: Environment variables (for command line startup)

Applicable scenario: You’re used to launching Cursor from terminal, or need to temporarily switch proxies

Windows (PowerShell):

$env:HTTP_PROXY="http://127.0.0.1:7890"
$env:HTTPS_PROXY="http://127.0.0.1:7890"
cursor

macOS/Linux:

export HTTP_PROXY=http://127.0.0.1:7890
export HTTPS_PROXY=http://127.0.0.1:7890
cursor

The advantage of this method is it doesn’t pollute global configuration—close the terminal and it’s gone.

Method 3: System proxy auto-detect (recommended for corporate networks)

Applicable scenario: Company IT department configured PAC file or transparent proxy

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Cursor actually supports reading system proxy, but it’s disabled by default. How to enable:

1. Find Cursor’s startup configuration file

   • Windows: Right-click desktop shortcut → Properties → Target
   • macOS: Edit /Applications/Cursor.app/Contents/Info.plist

2. Add launch parameter: --proxy-auto-detect

This way Cursor will automatically read system proxy configuration without manual address entry.

Method 4: Force ignore certificate errors (not recommended, but works)

Applicable scenario: Company proxy performs man-in-the-middle decryption of HTTPS traffic, causing certificate validation to fail

Serious warning: This method reduces security, use only temporarily!

Launch parameter: --ignore-certificate-errors

Full command (Windows):

& "C:\Users\YourUsername\AppData\Local\Programs\Cursor\Cursor.exe" --ignore-certificate-errors

With this parameter, Cursor won’t verify SSL certificates, bypassing many corporate proxy certificate issues. But remember, this is a last resort—avoid if possible.

The HTTP/2 Pitfall: Why Does Browser Work But Not Cursor?

This problem stumped me for two days.

The symptom: Browser opens OpenAI API perfectly fine, curl command returns data normally, but Cursor throws ERR_HTTP2_PROTOCOL_ERROR.

I later learned that the Electron version Cursor uses has a bug in HTTP/2 implementation, causing negotiation failures with servers in certain network environments.

Temporary solution: Force downgrade to HTTP/1.1

Method 1: Via launch parameter

cursor --disable-http2

Method 2: Modify proxy software configuration (using Clash as example)

Open Clash config file (config.yaml), find your proxy rules, and add:

proxies:
  - name: "Your proxy name"
    type: http
    server: 127.0.0.1
    port: 7890
    http-version: "1.1"  # Force HTTP/1.1

Restart Clash and Cursor after changes, and 90% of HTTP/2 errors will disappear.

Root solution: Wait for official Cursor fix, or downgrade version

Honestly, this bug has been reported dozens of times in Cursor’s GitHub Issues, and the team hasn’t directly addressed it.

If you really can’t stand it, you can downgrade to version 0.39.x, which has a relatively stable Electron version. The downside is no new features—you’ll need to weigh the tradeoff.

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Ultimate Solution for Corporate Network Environments

Corporate networks are the most troublesome scenario, combining all the previous problems: forced proxies, SSL man-in-the-middle, firewalls, internal DNS… each can make Cursor stop working.

I’ve compiled a configuration solution that works 100% in corporate environments:

Configuration checklist (execute in order)

1. Get company proxy information

Ask IT department for this information:

• Proxy server address and port (e.g., proxy.company.com:8080)
• Whether username/password required
• Whether using PAC auto-configuration
• Whether SSL decryption is used (if so, get the root certificate)

2. Configure Cursor proxy

Add to settings.json:

{
  "http.proxy": "http://username:[email protected]:8080",
  "https.proxy": "http://username:[email protected]:8080",
  "http.proxyStrictSSL": false
}

Note: If there’s SSL man-in-the-middle, you must add the http.proxyStrictSSL: false line.

3. Import company root certificate

If company has SSL decryption, you must import the root certificate, otherwise Cursor will keep reporting certificate verify failed.

Windows:

1. Double-click root certificate file (.crt or .cer)
2. Select “Install Certificate” → “Local Machine” → “Trusted Root Certification Authorities”

macOS:

sudo security add-trusted-cert -d -r trustRoot -k /Library/Keychains/System.keychain company-root-cert.crt

4. Add launch parameter combination

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Create a launch script (Windows uses .bat, macOS/Linux uses .sh):

Windows (start-cursor.bat):

@echo off
set HTTP_PROXY=http://proxy.company.com:8080
set HTTPS_PROXY=http://proxy.company.com:8080
start "" "C:\Users\YourUsername\AppData\Local\Programs\Cursor\Cursor.exe" --proxy-auto-detect --disable-http2

macOS/Linux (start-cursor.sh):

#!/bin/bash
export HTTP_PROXY=http://proxy.company.com:8080
export HTTPS_PROXY=http://proxy.company.com:8080
/Applications/Cursor.app/Contents/MacOS/Cursor --proxy-auto-detect --disable-http2

From now on, use this script to launch Cursor—don’t click the icon directly.

5. Test connection

After launching, open Cursor’s developer tools (Ctrl+Shift+I or Cmd+Option+I), switch to Network tab, ask the AI any question, and see if requests return normally.

If still not working, go back to the log file (path mentioned earlier), find the latest error information, and go through the troubleshooting steps again.

Summary

After all that, Cursor’s network problems really boil down to four pitfalls:

1. Proxy misconfigured → Check http.proxy and environment variables
2. HTTP/2 protocol conflict → Add --disable-http2 parameter
3. SSL certificate validation failed → Import root certificate or temporarily disable verification
4. Corporate network restrictions → Combination: proxy + certificate + launch parameters

I spent three days originally because I didn’t know these four problems could stack. Fixed the proxy, HTTP/2 still errored; disabled HTTP/2, certificate issues appeared; imported certificate, DNS wouldn’t resolve… Each time I thought I solved it, just got a different error.

Looking back now, if I’d followed this article’s troubleshooting order from the start, it would’ve taken half an hour.

One last thing: Don’t treat error logs as decorations. Every time you encounter a problem, first go to the logs to find the latest ERROR—90% of problem answers are there. For the remaining 10% you can’t solve, take the logs to GitHub Issues or Discord—others can help you locate issues faster too.

Network problems aren’t scary—what’s scary is flailing around blindly. Hope this article saves you those 72 hours.

8 min read · Published on: Jan 19, 2026 · Modified on: Feb 4, 2026

Easton

Technology