Copilot Chat's "Restore Checkpoint" and edit previous message features do not work

[aaronfranke]

• Copilot Chat Extension Version: 0.36.2
• VS Code Version: 1.108.2
• OS Version: Windows 11 25H2 build 26200.7623
• Feature (e.g. agent/edit/ask mode): Any/all
• Selected model (e.g. GPT 4.1, Claude 3.7 Sonnet): Any/all

Steps to Reproduce:

1. Have a chat with some history.
2. Scroll up to a previous message and click "Restore Checkpoint". Nothing happens.
3. Click on one of your messages and click on it to edit.
4. It becomes editable, and you can change the text.
5. When clicking submit, a popup dialog appears asking if you're okay with deleting history and undoing changes to files.
6. Accept this dialog. The files revert, but the contents of the chat window do not revert.

I believe these are all symptoms of the same bug. This broken state persists across many chats and multiple starts.

This issue microsoft/vscode-copilot-release#9391 indicates that the feature was implemented last year, but it appears to already be broken.

Also, it would be nice if there was an option to revert the chat without reverting the files on disk. I want to regain the earlier context I gave it as conversation history, but discard the latest messages where I went on a tangent.

[vs-code-engineering]

Thanks for creating this issue! It looks like you may be using an old version of VS Code; the latest stable release is 1.109.0. Please try upgrading to the latest version and checking whether this issue remains.

Happy Coding!

[aaronfranke]

This also occurs on 1.109.0.

[abelmarnk]

I have the same issue, i'm using 1.109.0 as well.

Also, it would be nice if there was an option to revert the chat without reverting the files on disk. I want to regain the earlier context I gave it as conversation history, but discard the latest messages where I went on a tangent.

That feature would be good.

[justschen]

hmm I'm not seeing this, but this could be related to performance. if you're not able to repro with just 2 or 3 request, but see this consistently with longer history, then it is likely performance related and we can give that a look!

[aaronfranke]

This happens with conversations only a few messages long and conversations many dozens of messages long. It's also not a matter of performance, as the operation never completes, it's not a matter of it being slow.

[justschen]

you misunderstand my performance concern, but regardless some things that would help since we're not seeing this in stable or the latest insiders, and i can get to the bottom of this!

• maybe a video of your work flow, clicking thru what you're trying
• does it make a differece when there are edits to undo, or just the chat request.
• double check the chat version (latest is 0.37.2)