The agent frequently encounters exceptions after working on the plan

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1

When cursor is working, it sometimes opens a document and creates a new conversation, then quickly returns to the original conversation and reconnects to the previous round of conversation. This can cause the workspace to be filled with plan documents opened by cursor. After repeating this several times, it will crash with errors. Here is the request detail:

Request ID: 00d852c1-da60-4421-a37b-e738dee6713f
[internal] serialize binary: invalid int 32: 4294963248
NTe: [internal] serialize binary: invalid int 32: 4294963248
at tpf (vscode-file://vscode-app/c:/Users/28291/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9097:38348)
at Xmf (vscode-file://vscode-app/c:/Users/28291/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9097:37251)
at gpf (vscode-file://vscode-app/c:/Users/28291/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9098:5088)
at yva.run (vscode-file://vscode-app/c:/Users/28291/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9098:9098)
at async Wyt.runAgentLoop (vscode-file://vscode-app/c:/Users/28291/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:34198:57104)
at async ngc.streamFromAgentBackend (vscode-file://vscode-app/c:/Users/28291/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:34247:7835)
at async ngc.getAgentStreamResponse (vscode-file://vscode-app/c:/Users/28291/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:34247:8576)
at async OTe.submitChatMaybeAbortCurrent (vscode-file://vscode-app/c:/Users/28291/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9172:14624)
at async Xi (vscode-file://vscode-app/c:/Users/28291/AppData/Local/Programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:32996:3808)

2

Hi there!

We detected that this may be a bug report, so we’ve moved your post to the Bug Reports category.

To help us investigate and fix this faster, could you edit your original post to include the details from the template below?

Bug Report Template - Click to expand

Where does the bug appear (feature/product)?

  • Cursor IDE
  • Cursor CLI
  • Background Agent (GitHub, Slack, Web, Linear)
  • BugBot
  • Somewhere else…

Describe the Bug
A clear and concise description of what the bug is.

Steps to Reproduce
How can you reproduce this bug? We have a much better chance at fixing issues if we can reproduce them!

  1. …
  2. …
  3. …

Expected Behavior
What is meant to happen here that isn’t working correctly?

Screenshots / Screen Recordings
If applicable, attach images or videos (.jpg, .png, .gif, .mp4, .mov)

Operating System

  • Windows 10/11
  • MacOS
  • Linux

Version Information

  • For Cursor IDE: Menu → About Cursor → Copy
  • For Cursor CLI: Run agent about in your terminal
IDE:
Version: 2.xx.x
VSCode Version: 1.105.1
Commit: ......

CLI:
CLI Version 2026.01.17-d239e66

For AI issues: which model did you use?
Model name (e.g., Sonnet 4, Tab…)

For AI issues: add Request ID with privacy disabled
Request ID: f9a7046a-279b-47e5-ab48-6e8dc12daba1
For Background Agent issues, also post the ID: bc-…

Additional Information
Add any other context about the problem here.

Does this stop you from using Cursor?

  • Yes - Cursor is unusable
  • Sometimes - I can sometimes use Cursor
  • No - Cursor works, but with this issue

The more details you provide, the easier it is for us to reproduce and fix the issue. Thanks!

4

Hey, thanks for the report.

This is a known issue on Windows. The serialize binary: invalid int 32 error happens when the Agent runs commands in the terminal and gets a bad exit code that can’t fit into an int32 during serialization.

Try switching to Command Prompt:

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

Just a heads up, this workaround doesn’t always help, especially in Plan mode with repeated operations. The team is aware of the issue.

We need a bit more info for the report:

  • Cursor version (Menu → About Cursor → Copy)
  • What task did you give the agent when this started?
  • Can you reproduce it consistently with certain prompts?

Main thread for this issue is here: Connection Error - Serialize Binary You can subscribe for updates.