Tool read_file not found

[MBarella]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

The AI Agent is not able to read any file at all, so it tries to fallback to cat, ls, sed or even git commands to read the file. It outputs Tool read_file not found. for every single file.

Steps to Reproduce

The bug seems to be random, but its not rare.

Expected Behavior

The agent reads the file using the read_file tool successfuly

Operating System

Windows 10/11

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.8.0-pre.29.patch.0 (user setup)
VSCode Version: 1.99.3
Commit: 0c7cdf10ce409d9639f6f607bfb776f248e14730
Date: 2025-10-16T08:14:25.861Z
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 10.0.26100

For AI issues: which model did you use?

Auto

For AI issues: add Request ID with privacy disabled

361e23f9-6253-450d-b1e6-1c5855bbd295

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

[deanrie]

Hey, thanks for the report.

A couple of questions to help us investigate:

• Does this happen in new chats, or only when loading existing ones?
• Have you tried switching to the stable version instead of the pre-release?

For now, you can try the stable version as a workaround if the issue persists.

[MBarella]

This can happen both in new and existing chats, it seems really random.

I haven’t tried the stable version, I understand that this can happen only on Nightly/Pre-release and that those versions aren’t supposed to work 100% at all times.

[MBarella]

@deanrie
It seems like this problem is related to Custom modes (atleast to me)…

[deanrie]

Thanks for the info, that’s very helpful.

[MBarella]

@deanrie
Quick update, on version 2.0.* it is still happening PLUS on worktrees now…
See the video below:

[deanrie]

Thanks for the info, we’ll look into it.

[Oliver_Blum]

I’m observing the same issue. The problem occurs reproducibly when using custom modes; the standard agent works fine.
For testing purposes, I created a custom mode without a prompt but with All Tools and model:auto. The problem occurs both with and without auto-run.

Version: 2.0.18
VSCode Version: 1.99.3
Commit: 8cb04d86d3ad91716fbaa6853f0c8ce3e64371d0
Date: 2025-10-27T15:23:27.332Z
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Darwin arm64 24.6.0

[Marco_Quintella]

Same happening here, but seems to be always in Custom Agent Mode

[lifipp]

same here!

Version: 2.0.43

VSCode Version: 1.99.3

Commit: 8e4da76ad196925accaa169efcae28c45454cce0

Date: 2025-10-30T18:49:27.589Z (3 days ago)

Electron: 34.5.8

Chromium: 132.0.6834.210

Node.js: 20.19.1

V8: 13.2.152.41-electron.0

OS: Darwin arm64 25.0.0

[Chis]

same as well
Version: 2.0.54 (Universal)
VSCode Version: 1.99.3
Commit: 7a31bffd467aa2d9adfda69076eb924e9062cb20
Date: 2025-11-03T22:40:44.657Z (20 hrs ago)
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Darwin arm64 23.4.0

[Michael_Kolinski]

I have the same problem, when working in the Agent Mode. It appeared after the 2.0 update. With any of the available models.

Version: 2.0.64 (Universal)
VSCode Version: 1.99.3
Commit: 25412918da7e74b2686b25d62da1f01cfcd27680
Date: 2025-11-06T04:35:14.424Z
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Darwin arm64 25.0.0

[CHeelan]

Same here.

Version: 2.0.69 (user setup)
VSCode Version: 1.99.3
Commit: 63fcac100bd5d5749f2a98aa47d65f6eca61db30
Date: 2025-11-07T18:21:29.650Z
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 10.0.26100