Claude Sonnet 4.5 Error

Bug Reports
1

Describe the Bug

When I use Sonnet 4.5 in Cursor on Windows, the model stops responding after a few short answers.

At first it replies normally to a couple of prompts, but after 3–5 messages it suddenly stops giving any response. The request is sent (I see the spinner / “thinking” state), but no answer ever appears and no error message is shown.

If I switch to another model (e.g. GPT), it works fine in the same project. The problem only happens with Sonnet 4.5.

Steps to Reproduce

When I use Sonnet 4.5 in Cursor on Windows, the model stops responding after a few short answers.

At first it replies normally to a couple of prompts, but after 3–5 messages it suddenly stops giving any response. The request is sent (I see the spinner / “thinking” state), but no answer ever appears and no error message is shown.

If I switch to another model (e.g. GPT), it works fine in the same project. The problem only happens with Sonnet 4.5.

Operating System

Windows 10/11

Current Cursor Version (Menu → About Cursor → Copy)

Cursor v.2.0.0 windows

Does this stop you from using Cursor

Yes - Cursor is unusable

2

Hey, thanks for the report. The symptoms you’re describing (spinner with no response and no error message) usually point to a network connectivity issue.

Let’s take a look:

  1. Run network diagnostics:
  • Cursor Settings → Network → Run Diagnostics
  • Share the results here
  1. Collect diagnostic information:
  • After a failed request, copy the Request ID: chat menu (top right) → Copy Request ID
  • Check for console errors: Help → Toggle Developer Tools → Console tab (take a screenshot of any errors)

Additional checks:

  • Temporarily disable your firewall/antivirus or VPN
  • If you have MCP servers configured, try disabling them temporarily (Cursor Settings → Tools & MCP)

Please share the diagnostics results and the Request ID so we can continue investigating.

3

Testleri yaptım hiç bir network sorunum yok.

Request ID: e2ccbd31-b955-4bc6-b942-fe91d124050a
{“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 QJc.$endAiConnectTransportReportError (vscode-file://vscode-app/c:/Program%20Files/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:4989:399336)
at Ywo._doInvokeHandler (vscode-file://vscode-app/c:/Program%20Files/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:492:36007)
at Ywo._invokeHandler (vscode-file://vscode-app/c:/Program%20Files/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:492:35749)
at Ywo._receiveRequest (vscode-file://vscode-app/c:/Program%20Files/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:492:34514)
at Ywo._receiveOneMessage (vscode-file://vscode-app/c:/Program%20Files/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:492:33336)
at GDt.value (vscode-file://vscode-app/c:/Program%20Files/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:492:31429)
at _e._deliver (vscode-file://vscode-app/c:/Program%20Files/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:49:2962)
at _e.fire (vscode-file://vscode-app/c:/Program%20Files/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:49:3283)
at ggt.fire (vscode-file://vscode-app/c:/Program%20Files/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:4974:12156)
at MessagePort. (vscode-file://vscode-app/c:/Program%20Files/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:7498:18439)