I am using Opus 4.5 in Cursor and am consistently encountering an error that prevents the model from responding only when building a plan or running in Agent mode.
The model works correctly in Plan mode, but once I proceed to Build the plan or switch to Agent mode, the request fails and no response is returned.
Steps to Reproduce
Select Opus 4.5 as the active model
Enter a prompt and run it in Plan mode (works as expected)
Click Build Plan or switch to Agent mode
Observe that the request fails and the error ERROR_OPENAI – Unable to reach the model provider is returned
Expected Behavior
Opus 4.5 should respond successfully in all modes, including Plan, Build Plan, and Agent mode.
Operating System
Windows 10/11
Current Cursor Version (Menu → About Cursor → Copy)
For AI issues: add Request ID with privacy disabled
Request ID: 3fa84d1b-92a7-4370-b727-644a7351b192
{“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}
I followed these steps, but I still have the same issue. I don’t have the Nx installed as well
Also, I disabled HTTP/2.
I am from Turkey, and I don’t use vpn or proxy, and I don’t have any extensions installed. Everything was working fine from yesterday; this issue started today
Request ID: 93f75c79-d20d-4c66-ba57-fce4810f73dd
{“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 szc.$endAiConnectTransportReportError (vscode-file://vscode-app/c:/Users/User/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:12375:456006)
at xBo._doInvokeHandler (vscode-file://vscode-app/c:/Users/User/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:13027:22831)
at xBo._invokeHandler (vscode-file://vscode-app/c:/Users/User/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:13027:22573)
at xBo._receiveRequest (vscode-file://vscode-app/c:/Users/User/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:13027:21335)
at xBo._receiveOneMessage (vscode-file://vscode-app/c:/Users/User/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:13027:20152)
at zLt.value (vscode-file://vscode-app/c:/Users/User/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:13027:18244)
at Ee._deliver (vscode-file://vscode-app/c:/Users/User/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:49:2962)
at Ee.fire (vscode-file://vscode-app/c:/Users/User/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:49:3283)
at Tvt.fire (vscode-file://vscode-app/c:/Users/User/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:12360:12156)
at MessagePort. (vscode-file://vscode-app/c:/Users/User/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:15027:18433)
I can see network diagnostics pass but the ConnectError: [unavailable] still happens specifically in Agent/Build mode. This pattern suggests the issue may be regional.
Could you please try one more thing:
Test in Ask mode (not Agent) - does the same model work there?
Try launching with a clean profile from terminal:
cursor --user-data-dir=%TEMP%\cursor-test
Then test Agent mode in this fresh instance.
Share 2-3 new Request IDs from failed attempts after the clean profile test.
We’re tracking similar regional issues and the request IDs will help us investigate further.
