IDE hangs after automatic MCP browser test,

Support Bug Reports
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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Seeing a new issue this week on Windows: after the agent runs an MCP Browser test in our React Native project, the IDE hangs right when the test finishes, and we have to force-kill the process.
Has anyone else run into this? Any fixes, settings, or version changes that helped?

OS: Windows
Brower: Chrome
Cursor Version:

Version: 2.3.35 (system setup)
VSCode Version: 1.105.1
Commit: cf8353edc265f5e46b798bfb276861d0bf3bf120
Date: 2026-01-13T07:39:18.564Z
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Windows_NT x64 10.0.26200

Steps to Reproduce

ask an agent to run a test on a program that’s written with React Native.

Expected Behavior

It’s not supposed to hang.

Operating System

Windows 10/11

Current Cursor Version (Menu → About Cursor → Copy)

Version: 2.3.35 (system setup)
VSCode Version: 1.105.1
Commit: cf8353edc265f5e46b798bfb276861d0bf3bf120
Date: 2026-01-13T07:39:18.564Z
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Windows_NT x64 10.0.26200

For AI issues: which model did you use?

Opus 4.5

For AI issues: add Request ID with privacy disabled

Dont know whow to get that

Additional Information

Very repeatable.

Does this stop you from using Cursor

Yes - Cursor is unusable

3

Hey, thanks for the detailed report. We’ve seen a similar issue before with the Browser Tab, and it was fixed in later updates. We need a bit more info to diagnose this:

Check MCP servers:

  • Settings > Cursor Settings > Tools & MCP. Which servers are configured?
  • Try disabling all MCP servers, restart Cursor, and reproduce the issue
  • In other similar cases, MCP servers (especially GitHub and Atlassian) caused the agent to freeze

We need logs:

  • When the agent starts the test, open Help > Toggle Developer Tools > Console tab
  • Take a screenshot of the logs at the moment it freezes, or right after

Request ID:

  • If you can do it before it freezes, open the chat menu (three dots in the top right) > Copy Request ID and send it here

Temporary workaround:
If the issue is related to MCP servers, try working with MCP disabled while the team investigates.

Send the results of these checks. It’ll help us figure out if this is a known MCP bug on Windows or if we need to dig deeper.

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