Cursor Chat Not Working - Error in Network Diagnositics

Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Whenever I try to use Cursor Chat, it just loads and loads then just returns nothing. I was told to check the Network Diagnostics, there I found connectivity issues for Cursor Chat, Background Agent and more.

Steps to Reproduce

Open cursor on Ubuntu, open any project and try to ask Cursor Chat anything about the project. Also open Cursor Settings > Network > Run Diagnostics.

Expected Behavior

It should return something about what you’ve asked Cursor Chat or even an error explaining what went wrong.

Screenshots / Screen Recordings

Screenshot from 2025-10-23 13-50-42.png
Screenshot from 2025-10-23 13-50-42.png730Ă—994 119 KB

Operating System

Linux

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.7.53
VSCode Version: 1.99.3
Commit: ab6b80c19b51fe71d58e69d8ed3802be587b3410
Date: 2025-10-20T19:15:58.572Z
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Linux x64 6.8.0-85-generic

Does this stop you from using Cursor

Yes - Cursor is unusable

2

Hey, thanks for the report. I can see HTTP/1.1 is enabled, but you’re getting ETIMEDOUT errors — this means connections to Cursor’s backend services are being blocked at the network level before they complete.

Please check:

  1. Are you behind a corporate firewall or proxy? If yes, IT may need to whitelist Cursor’s domains.
  2. Test direct connectivity from the terminal:
    curl -v https://api2.cursor.sh
    Does it succeed or time out?
  3. Check active firewall/VPN:
    • Temporarily disable UFW: sudo ufw disable (for testing only)
    • If using a VPN, try disabling it
    • Check if any security software is running
  4. Network location: Are you on a restricted network (university, office, public Wi‑Fi with filtering)?

Quick fixes:

  1. Switch DNS to Google/Cloudflare:
    1. System Preferences → Network → Advanced → DNS
    2. Add 8.8.8.8 or 1.1.1.1
    3. Click OK, then restart Cursor

Since DNS and SSL pass but API/Chat/Agent time out, something is likely blocking outbound HTTPS to Cursor’s backend. Common causes:

  • Corporate firewall policies
  • ISP‑level filtering
  • VPN interference
  • Local firewall rules (ufw/iptables)

Let me know the results of the connectivity test and details about your network setup.

3

Hello Deanrie,
Adding 8.8.8.8 to my DNS settings resolved the issue.

I’m currently not behind any corporate firewall and I’m not using any VPN.
And here are the logs from running the curl command:

Trying 23.22.226.177:443…

  • Connected to api2.cursor.sh (23.22.226.177) port 443 (#0)
  • ALPN, offering h2
  • ALPN, offering http/1.1
  • CAfile: /etc/ssl/certs/ca-certificates.crt
  • CApath: /etc/ssl/certs
  • TLSv1.0 (OUT), TLS header, Certificate Status (22):
  • TLSv1.3 (OUT), TLS handshake, Client hello (1):
  • TLSv1.2 (IN), TLS header, Certificate Status (22):
  • TLSv1.3 (IN), TLS handshake, Server hello (2):
  • TLSv1.2 (IN), TLS header, Finished (20):
  • TLSv1.2 (IN), TLS header, Supplemental data (23):
  • TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
  • TLSv1.2 (IN), TLS header, Supplemental data (23):
  • TLSv1.3 (IN), TLS handshake, Certificate (11):
  • TLSv1.2 (IN), TLS header, Supplemental data (23):
  • TLSv1.3 (IN), TLS handshake, CERT verify (15):
  • TLSv1.2 (IN), TLS header, Supplemental data (23):
  • TLSv1.3 (IN), TLS handshake, Finished (20):
  • TLSv1.2 (OUT), TLS header, Finished (20):
  • TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
  • TLSv1.2 (OUT), TLS header, Supplemental data (23):
  • TLSv1.3 (OUT), TLS handshake, Finished (20):
  • SSL connection using TLSv1.3 / TLS_AES_128_GCM_SHA256
  • ALPN, server accepted to use h2
  • Server certificate:
  • subject: CN=api2.cursor.sh
  • start date: Dec 11 00:00:00 2024 GMT
  • expire date: Jan 10 23:59:59 2026 GMT
  • subjectAltName: host “api2.cursor.sh” matched cert’s “api2.cursor.sh”
  • issuer: C=US; O=Amazon; CN=Amazon RSA 2048 M03
  • SSL certificate verify ok.
  • Using HTTP2, server supports multiplexing
  • Connection state changed (HTTP/2 confirmed)
  • Copying HTTP/2 data in stream buffer to connection buffer after upgrade: len=0
  • TLSv1.2 (OUT), TLS header, Supplemental data (23):
  • TLSv1.2 (OUT), TLS header, Supplemental data (23):
  • TLSv1.2 (OUT), TLS header, Supplemental data (23):
  • Using Stream ID: 1 (easy handle 0x5c5c3fa249f0)
  • TLSv1.2 (OUT), TLS header, Supplemental data (23):

GET / HTTP/2
Host: api2.cursor.sh
user-agent: curl/7.81.0
accept: /

  • TLSv1.2 (IN), TLS header, Supplemental data (23):
  • TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
  • TLSv1.2 (IN), TLS header, Supplemental data (23):
  • Connection state changed (MAX_CONCURRENT_STREAMS == 128)!
  • TLSv1.2 (OUT), TLS header, Supplemental data (23):
  • TLSv1.2 (IN), TLS header, Supplemental data (23):
    < HTTP/2 200
    < date: Thu, 23 Oct 2025 13:14:04 GMT
    < content-type: text/plain
    < content-length: 131
    < vary: Origin
    < access-control-allow-credentials: true
    < access-control-expose-headers: Grpc-Status, Grpc-Message, Grpc-Status-Details-Bin, Content-Encoding, Connect-Content-Encoding, traceparent, backend-traceparent, x-amzn-trace-id, x-request-id
    <
  • TLSv1.2 (IN), TLS header, Supplemental data (23):
  • Connection #0 to host api2.cursor.sh left intact
1 Like