Checkpoints are still broken

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

The restore checkpoint button breaks in random situations. I’m not sure what causes it to sometimes work and not others.

Steps to Reproduce

  1. Ask the agent to make a change
  2. Use the Restore checkpoint button
  3. The file does not change, it remains as it was, the git diff remains.

Operating System

MacOS

Version Information

Version: 3.17.19
VS Code Extension API: 1.128.0
Commit: ae3a2b7231dd56194447fe4570dfdc61640b1e90
Date: 2026-08-24T06:42:14.583Z
Layout: Agent Window
Build Type: Stable
Release Track: Default
Electron: 40.10.3
Chromium: 144.0.7559.236
Node.js: 24.15.0
V8: 14.4.258.32-electron.0
xterm.js: 6.1.0-beta.291
OS: Darwin arm64 25.6.0

For AI issues: which model did you use?

Composer 2.5

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

Hey @jkpe, thanks for the report.

A quick question that would help us narrow this down: are you working over Remote SSH, or on files that live on a network mount (NFS or similar)?

Connection drops in those setups are the most common cause we’ve seen for a checkpoint’s saved state getting corrupted, which then makes Restore silently do nothing while the git diff stays put.

We have a fix for exactly that corruption case targeted for 3.18.

Hi Colin!

Just on my Mac, local file system.

Happy to try and recreate the problem, let me know which debugging steps will help you to identify what is happening in the background.

Thanks! Next time a restore doesn’t take effect, could you:

  1. Open the developer console first (Help → Toggle Developer Tools → Console)
  2. Try to restore the checkpoint
  3. Copy everything in the console containing “[composer]” and paste it here

A restore that worked prints “Processed file … for revert operation” lines. If you instead see “No original file state found” or an error, that tells us exactly which case you’re hitting.

Two more things that would help:

  • Do the affected files include any .ipynb notebooks? (Those aren’t supported for checkpoint restore.)
  • Does it tend to happen in long conversations, after reloading the window or returning to an older chat, or in sessions where subagents made some of the edits?