Sonnet models unreachable

Support Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Since August 18, Cursor has been unable to reach Sonnet 4. I get the error:

Request ID: 162246c7-9d92-4c84-a795-3f1472cf62b3
{"error":"ERROR_OPENAI","details":{"title":"Unable to reach the model provider","detail":"We're having trouble connecting to the model provider. This might be temporary - please try again in a moment.","additionalInfo":{},"buttons":[],"planChoices":[]},"isExpected":false}
ConnectError: [unavailable] Error
    at yel.$endAiConnectTransportReportError (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:4918:251962)
    at tcr._doInvokeHandler (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:493:20860)
    at tcr._invokeHandler (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:493:20602)
    at tcr._receiveRequest (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:493:19367)
    at tcr._receiveOneMessage (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:493:18189)
    at TSt.value (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:493:16283)
    at ve._deliver (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:49:2962)
    at ve.fire (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:49:3283)
    at Mst.fire (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:4905:12154)
    at d.onmessage (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:7030:18167)

I have tried:

  • Two different macOS PCs
  • Four different networks
  • With and without VPNs
  • HTTP/2, HTTP/1.1, and HTTP/1.0 modes
  • Successful diagnostic runs
  • Toggling cursor.general.disableHttp2
  • New chat window
  • Rebooting
  • Confirming Anthropic’s status is operational via https://status.anthropic.com/
  • Confirming OpenRouter’s status (in case Cursor uses that) is operational via https://status.openrouter.ai/

Non-Anthropic models have been working fine, but not Sonnet 4.

And when I tried Sonnet 3.7 with a simple message like “What model are you” and no added context, it would fail, complaining that my message was too long.

Am I really the only one experiencing this for several days? Why? And how do I fix it?

Also, the usage is still deducted from my account, even though my account history shows those requests failed.

Steps to Reproduce

  1. Use Sonnet 4 in Ask or Agent mode.
  2. Enter any prompt.

Expected Behavior

I expect it to work like it was working before August 18.

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.4.5 (Universal)
VSCode Version: 1.99.3
Commit: af58d92614edb1f72bdd756615d131bf8dfa5290
Date: 2025-08-13T02:08:56.371Z
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Darwin arm64 24.6.0

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

2

The “Sometimes” of this is that Cursor continues to work without the AI features, or different models. But this problem is an “always” with Sonnet 4.