Agent error: serialize binary invalid int 32

[Srikanth_Gone]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Request ID: 26a56fcc-5ab9-48da-823c-de6976fdb7bd

Error: [internal] serialize binary: invalid int 32: 3762504530

When i try to use the cursor with playwright MCP or some other agent functionality i’m getting internal error and not completing the task.

Version: 2.4.22 (user setup)
VSCode Version: 1.105.1
Commit: 618c607a249dd7fd2ffc662c6531143833bebd40
Date: 2026-01-26T22:51:47.692Z
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 10.0.26100

Steps to Reproduce

Use any Playwright MCP and make Test case design

Screenshots / Screen Recordings

Operating System

Windows 10/11

Version Information

Version: 2.4.22 (user setup)
VSCode Version: 1.105.1
Commit: 618c607a249dd7fd2ffc662c6531143833bebd40
Date: 2026-01-26T22:51:47.692Z
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 10.0.26100

For AI issues: which model did you use?

Version: 2.4.22 (user setup)
VSCode Version: 1.105.1
Commit: 618c607a249dd7fd2ffc662c6531143833bebd40
Date: 2026-01-26T22:51:47.692Z
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 10.0.26100

For AI issues: add Request ID with privacy disabled

Request ID: 26a56fcc-5ab9-48da-823c-de6976fdb7bd

Does this stop you from using Cursor

Yes - Cursor is unusable

[deanrie]

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 incorrect exit code that doesn’t fit into an int32 during serialization.

Try switching to Command Prompt:

1. Fully close Cursor
2. Open Settings with Ctrl+,
3. Find terminal.integrated.defaultProfile.windows
4. Set it to “Command Prompt” instead of PowerShell
5. Restart Cursor

Just a heads-up, this workaround doesn’t always help, especially with long commands or more complex MCP actions. The team knows about the issue, but there’s no fix yet.

If it still doesn’t work, please share:

• The exact command Playwright MCP tried to run (or what you asked the Agent to do)
• A screenshot of your terminal settings (Settings > Terminal > Integrated: Default Profile: Windows)

Main thread with updates and other affected users: Connection Error - Serialize Binary
You can subscribe there to keep track of updates.

[Srikanth_Gone]

Hi Dean, i tried above solutions by updating to Powershell to command prompt still error is coming.

[Srikanth_Gone]

@deanrie , Few of my colleagues are using this Cursor AI and MCP and they not facing this issue