Connection error in Agent

Support Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Hi, I’ve been having a productive Agent coding session today, until I started getting Connection Errors. “Connection failed. If the problem persists, please check your internet connection or VPN”. It’s not the VPN – I’ve tried with and without. “curl -v https://api2.cursor.sh” works fine.

Here is what’s in the Cursor dev console:
workbench.desktop.main.js:7151 [AiService] streamResponse ConnectError: [internal] Failed to convert JavaScript value Undefined into rust type String
at dZc.$endAiConnectTransportReportError (workbench.desktop.main.js:6330:408452)
at MPo._doInvokeHandler (workbench.desktop.main.js:7180:11314)
at MPo._invokeHandler (workbench.desktop.main.js:7180:11056)
at MPo._receiveRequest (workbench.desktop.main.js:7180:9818)
at MPo._receiveOneMessage (workbench.desktop.main.js:7180:8635)
at mPt.value (workbench.desktop.main.js:7180:6727)
at _e._deliver (workbench.desktop.main.js:49:2962)
at _e.fire (workbench.desktop.main.js:49:3283)
at Gmt.fire (workbench.desktop.main.js:6315:12156)
at MessagePort. (workbench.desktop.main.js:8972:18439)
workbench.desktop.main.js:6880 [transport] Stream response error ConnectError: [internal] Failed to convert JavaScript value Undefined into rust type String
at dZc.$endAiConnectTransportReportError (workbench.desktop.main.js:6330:408452)
at MPo._doInvokeHandler (workbench.desktop.main.js:7180:11314)
at MPo._invokeHandler (workbench.desktop.main.js:7180:11056)
at MPo._receiveRequest (workbench.desktop.main.js:7180:9818)
at MPo._receiveOneMessage (workbench.desktop.main.js:7180:8635)
at mPt.value (workbench.desktop.main.js:7180:6727)
at _e._deliver (workbench.desktop.main.js:49:2962)
at _e.fire (workbench.desktop.main.js:49:3283)
at Gmt.fire (workbench.desktop.main.js:6315:12156)
at MessagePort. (workbench.desktop.main.js:8972:18439)
{arch: ‘arm64’, platform: ‘darwin’, channel: ‘stable’, client_version: ‘2.1.19’, generationUUID: ‘af06bcda-2a14-49b4-bd85-b59de3dd6536’, …}
workbench.desktop.main.js:6880 [transport] Automatic bug report submitted for unexpected connection error
{arch: ‘arm64’, platform: ‘darwin’, channel: ‘stable’, client_version: ‘2.1.19’, requestId: ‘af06bcda-2a14-49b4-bd85-b59de3dd6536’, …}
workbench.desktop.main.js:4064 [composer] Error in AI response: undefined ConnectError: [internal] Failed to convert JavaScript value Undefined into rust type String
at dZc.$endAiConnectTransportReportError (workbench.desktop.main.js:6330:408452)
at MPo._doInvokeHandler (workbench.desktop.main.js:7180:11314)
at MPo._invokeHandler (workbench.desktop.main.js:7180:11056)
at MPo._receiveRequest (workbench.desktop.main.js:7180:9818)
at MPo._receiveOneMessage (workbench.desktop.main.js:7180:8635)
at mPt.value (workbench.desktop.main.js:7180:6727)
at _e._deliver (workbench.desktop.main.js:49:2962)
at _e.fire (workbench.desktop.main.js:49:3283)
at Gmt.fire (workbench.desktop.main.js:6315:12156)
at MessagePort. (workbench.desktop.main.js:8972:18439)
workbench.desktop.main.js:6880 [composer] Error in AI response ConnectError: [internal] Failed to convert JavaScript value Undefined into rust type String
at dZc.$endAiConnectTransportReportError (workbench.desktop.main.js:6330:408452)
at MPo._doInvokeHandler (workbench.desktop.main.js:7180:11314)
at MPo._invokeHandler (workbench.desktop.main.js:7180:11056)
at MPo._receiveRequest (workbench.desktop.main.js:7180:9818)
at MPo._receiveOneMessage (workbench.desktop.main.js:7180:8635)
at mPt.value (workbench.desktop.main.js:7180:6727)
at _e._deliver (workbench.desktop.main.js:49:2962)
at _e.fire (workbench.desktop.main.js:49:3283)
at Gmt.fire (workbench.desktop.main.js:6315:12156)
at MessagePort. (workbench.desktop.main.js:8972:18439)
{arch: ‘arm64’, platform: ‘darwin’, channel: ‘stable’, client_version: ‘2.1.19’, requestId: ‘af06bcda-2a14-49b4-bd85-b59de3dd6536’, …}
workbench.desktop.main.js:4064 [composer] Failed to get complete AI response
workbench.desktop.main.js:6880 [composer] Chat incomplete or aborted
{arch: ‘arm64’, platform: ‘darwin’, channel: ‘stable’, client_version: ‘2.1.19’, requestId: ‘af06bcda-2a14-49b4-bd85-b59de3dd6536’, …}

Steps to Reproduce

It fails every time right now.

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

Version: 2.1.19
VSCode Version: 1.105.1
Commit: 39a966b4048ef6b8024b27d4812a50d88de29cc0
Date: 2025-11-21T22:59:02.376Z
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Darwin arm64 23.6.0

For AI issues: which model did you use?

Auto, doesn’t seem to matter

For AI issues: add Request ID with privacy disabled

Request ID: c2872d02-4ff6-44db-8c20-73fffee4c681
ConnectError: [internal] Failed to convert JavaScript value Undefined into rust type String
at dZc.$endAiConnectTransportReportError (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:6330:408452)
at MPo._doInvokeHandler (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:7180:11314)
at MPo._invokeHandler (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:7180:11056)
at MPo._receiveRequest (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:7180:9818)
at MPo._receiveOneMessage (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:7180:8635)
at mPt.value (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:7180:6727)
at _e._deliver (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:49:2962)
at _e.fire (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:49:3283)
at Gmt.fire (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:6315:12156)
at MessagePort. (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:8972:18439)Request ID: c2872d02-4ff6-44db-8c20-73fffee4c681
ConnectError: [internal] Failed to convert JavaScript value Undefined into rust type String
at dZc.$endAiConnectTransportReportError (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:6330:408452)
at MPo._doInvokeHandler (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:7180:11314)
at MPo._invokeHandler (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:7180:11056)
at MPo._receiveRequest (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:7180:9818)
at MPo._receiveOneMessage (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:7180:8635)
at mPt.value (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:7180:6727)
at _e._deliver (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:49:2962)
at _e.fire (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:49:3283)
at Gmt.fire (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:6315:12156)
at MessagePort. (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:8972:18439)

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

2

FWIW, starting a new Agent session worked fine – it’s an issue in that specific session that persists across restarting Cursor.

3

Hey, thanks for the report and for sharing the error logs with your request ID, that will help the team investigate.

The good news is that you’ve already found a workaround: starting a new Agent session resolves the issue. This suggests the bug is likely tied to a specific session rather than a broader connection problem.

If you run into this again and starting a new session doesn’t help, let me know.

4

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