Solution: Cannot read properties of undefined (reading 'split')

[digitarald]

Users on older versions of Copilot Chat see an increased number of chat messages failing with Cannot read properties of undefined (reading 'split'). If your error traces show github.copilot-chat-0.11.1 you are NOT on the latest version.

⚠️ Both VS Code and the extension need to be updated, as the latest release of Copilot Chat requires the latest release of VS Code.

Double-check you have VS Code 1.86 and Copilot Chat 0.12 and there are no blue notification dots for Restart to update!

Update your VS Code (Command: Check for Updates...) + Copilot Chat extension (Command: Extensions: Update All Extensions). Close and re-open VS Code just to make sure, as this applies any pending updates.

Common update blockers:

• Auto-updates disabled: Check settings extensions.autoCheckUpdates and update.mode
• Running VS Code as administrator will prevent updates: Don't run as administrator.
• Running it directly from macOS' Downloads folder (read-only): Drag the VS Code app to Applications folder.
• Legacy version with updates disabled on enterprise managed machine: Re-install if you have the rights or check with IT.

If you can't update, please share what blocks you from updating here so we can better understand and improve this process in the future.

[Jjarrard]

Reload fixed mine, not sure why VSCode didn't let me know.

[tairosonloa]

Reload fixed mine, not sure why VSCode didn't let me know.

Exact the same. I suggest adding some way to let the user know they have to update the extension, like using a vscode notification

[Advitya17]

Same issue

[beshur]

Reload and relogin does not fix this for me

[preyashpatel]

Reload and relogin does not fix this for me

[beshur]

Sorry, my bad, it works after plugin update

[fisforfaheem]

I am on VS code insiders and copilot pre release , still getting this error again and again

[1Ckpwee]

I didn't reload vscode, but it works when I open a new copilot chat session.

[altugbakan]

Just use the "+" button to open a new window to fix this issue, I'm guessing this is due to old chat format not working with the new code.

[starball5]

Duplicate of #796 (comment)

Related on Stack Overflow: Cannot read properties of undefined (reading 'split') with VSCode Copilot