[Critical Bug] Pro+ Plan: "Internal Error", HTTP/2 Failure & Serialization Error (Request ID: 22f6e890-8c0f-4565-bcd3-bf9ce4658694)

Support Bug Reports
,
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

In the Pro+ plan, Cursor IDE constantly pops up an “An unexpected error occurred on our servers” error, rendering all AI features (like Chat, Agent) completely unusable. Network diagnostics show HTTP/2 connection failure, and the error log indicates an underlying binary serialization error: [internal] serialize binary: invalid int 32: 3221225477.

Steps to Reproduce

In Cursor IDE, perform any action that triggers the AI backend service (e.g., ask a question in Chat, run a command that requires Agent analysis).
The operation is immediately cancelled, and the “Internal Error” dialog pops up.
Go to Settings > Network, click Run Diagnostic. The HTTP/2 check will fail.
Click Show Logs in the error dialog to see the serialization error stack trace.

Expected Behavior

AI features should work normally. A stable connection to the backend servers should be established without serialization errors.

Screenshots / Screen Recordings

image.png
image.png1748×830 54.7 KB

Operating System

Windows 10/11

Version Information

Version: 2.4.27 (user setup)
VSCode Version: 1.105.1
Commit: 4f2b772756b8f609e1354b3063de282ccbe7a690
Date: 2026-01-31T21:24:58.143Z
Build Type: Stable
Release Track: Default
Electron: 39.2.7
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Windows_NT x64 10.0.26200

For AI issues: which model did you use?

AgentGPT-5.2 Codex High，GPT-5.2 Codex，Opus 4.5

For AI issues: add Request ID with privacy disabled

Request ID: 22f6e890-8c0f-4565-bcd3-bf9ce4658694
[internal] serialize binary: invalid int 32: 3221225477
LTe: [internal] serialize binary: invalid int 32: 3221225477
at $mf (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9095:38337)
at Fmf (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9095:37240)
at Xmf (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9096:5088)
at hva.run (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9096:9098)
at async qyt.runAgentLoop (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:34196:57104)
at async jpc.streamFromAgentBackend (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:34245:7695)
at async jpc.getAgentStreamResponse (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:34245:8436)
at async FTe.submitChatMaybeAbortCurrent (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9170:14623)
at async Ei (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:32994:3808)
This points to a binary serialization failure involving an invalid 32-bit integer value (3221225477).

Additional Information

  1. Network Environment: I am on a normal home network (or corporate network, if applicable). No VPN or special proxy is active. The network is stable for all other applications.
  2. Full Error Stack: Provided in the bug description above.
  3. Request ID Note: The detailed Request ID 22f6e890-8c0f-4565-bcd3-bf9ce4658694 is from the error log stream. The error dialog showed a different ID: 22fe890-8cdf-4565-bcd3-bfb9ce4658694.
  4. Contact Email: [email protected] (for follow-up).

Does this stop you from using Cursor

Yes - Cursor is unusable

3

Hey, thanks for the report. This is a known issue on Windows. The error happens when the Agent runs commands in the terminal and gets an exit code that doesn’t fit into int32 during serialization.

I need a bit more info:

  • What exactly were you trying to do in Agent when the error showed up? (I can see the go build command in the screenshot, but maybe there were other actions too.)
  • Can you share a screenshot of your terminal settings? (Settings > Terminal > Integrated: Default Profile: Windows)

Main thread with updates: Connection Error - Serialize Binary

6

I wanted the Agent to run go build and other compilation commands in the terminal to compile my Go code into executables. This workflow had been working perfectly until about two days ago, when it started consistently throwing this “Internal Error” the moment the Agent tries to execute the command. I’ve uninstalled and reinstalled many times, and checked my network settings, but it still doesn’t work. What should I do next?

image
image781×300 16.1 KB

7

You need to switch to another ide

8

@deanrie Can you help me solve this problem? I haven’t been able to use it properly for several days.

9

303

I’m having a similar problem. I’m a pro user and since yesterday I haven’t been able to use the cursor. The network connection test never finishes, it never fails, it just keeps processing. Regardless of what I set as the HTTP protocol. In the chat, after several minutes of processing, the VPN only fails.

image
image753×712 18.7 KB

10

It should be an issue with the cursor. Waiting for the technician’s reply. There’s no problem with answering questions or generating code, it’s just that problems occur immediately when executing terminal commands.

11

Thanks for the screenshot, but I need the terminal settings specifically. I don’t see any terminal settings in your settings.json.

Please check which terminal is being used right now:

Option 1 (via UI):

  1. Open Settings Ctrl+,
  2. In the search bar, type default profile windows
  3. Find Terminal > Integrated > Default Profile: Windows
  4. Tell me what value is set there (PowerShell / Command Prompt / Git Bash)

Option 2 (faster):
Add this line to your settings.json:

"terminal.integrated.defaultProfile.windows": "Command Prompt"

After that, fully restart Cursor and try again.

If that still doesn’t help, tell me which terminal you had before (most likely PowerShell by default).