Chat gets permanently disconnected after npm build

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Chat became fully disconnected whenever cursor is attempting to run npm run build.
Auto-Ran Command:
npm error code ENOENT
npm error syscall open
npm error path C:\Users\This PC\package.json
npm error errno -4058
npm error enoent Could not read package.json: Error: ENOENT: no such file or directory, open ‘C:\Users\This PC\package.json’
npm error enoent This is related to npm not being able to find a file.
npm error enoent
npm error A complete log of this run can be found in: C:\Users\This PC\AppData\Local\npm-cache_logs\2025-09-29T05_33_02_650Z-debug-0.log

Error
Request ID: 0cd06c1d-368e-45c1-aec6-720e68230e7f
ConnectError: [internal] Serialization error in aiserver.v1.StreamUnifiedChatRequestWithTools
at vscode-file://vscode-app/c:/Program%20Files/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:5222:370234

Steps to Reproduce

Run the build

“Cursor plugs in npm run build”

then as it runs the chat will be disconnected

Expected Behavior

Runs the build and if there are any error it will provide me feedback.

Screenshots / Screen Recordings

Operating System

Windows 10/11

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.7.12 (system setup)
VSCode Version: 1.99.3
Commit: b3f1951240d5016648330fab51192dc03e8d7050
Date: 2025-09-28T00:58:08.696Z
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Windows_NT x64 10.0.22631

For AI issues: which model did you use?

Auto

For AI issues: add Request ID with privacy disabled

Request ID: 2e668e96-0a41-4117-a780-6a4aeeac14e3
ConnectError: [internal] Serialization error in aiserver.v1.StreamUnifiedChatRequestWithTools
at vscode-file://vscode-app/c:/Program%20Files/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:5222:370234

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

A post was merged into an existing topic: Serialization error