Connection Errors

Support Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

every time a Sonnet or Composer agent interracts with a terminal; a Connection Error occurs and the agent’s chat becomes useless and I have to start a new chat entirely; i was not having this issue with Opus agents; the issue is forcing me to use Opus even for menial tasks which of course is driving my usage through the roof; i have to instruct these agents to NOT interact with terminals at all

Steps to Reproduce

just by telling an agent chat to do something and then it inevitably wants to run a test or read terminal output

Expected Behavior

i expect these agents to be able to interract with terminals without Connection Errors that kill chats

Screenshots / Screen Recordings

Cursor Connection Error.jpg
Cursor Connection Error.jpg1286×1424 164 KB

Operating System

Windows 10/11

Current Cursor Version (Menu → About Cursor → Copy)

Version: 2.3.14 (system setup)
VSCode Version: 1.105.1
Commit: b3e9fe6c37659159fc2dec9ae643d74c25e5d0d0
Date: 2025-12-29T23:26:25.365Z
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 10.0.19045

For AI issues: which model did you use?

Sonnet and Composer

For AI issues: add Request ID with privacy disabled

c85d3e71-d0ce-4909-94ee-04654ece1857

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

2

Hey, thanks for the report.

This is a known issue on Windows when agents interact with a PowerShell terminal. The team is already working on a fix. It shows up most often when the agent reads terminal output or runs certain commands.

Workaround: try setting Git Bash or another shell (not PowerShell) as the default terminal in Cursor:

  1. Open Settings Ctrl+,
  2. Search for terminal.integrated.defaultProfile.windows
  3. Change it to “Git Bash” or “Command Prompt”

Also, to help us diagnose it, can you share which exact commands the agent runs right before it crashes? Please check the terminal history right before the Connection Error shows up.