Q: Quarto VS Code extension LSP crashes: TypeError: Cannot read properties of null (reading 'map')

[davidjanmassgov]

Description

What happened

The Quarto VS Code extension’s language server (LSP) starts, then immediately errors and shuts down. This only started happening today. VS Code shows:

Client Quarto LSP: connection to server is erroring. Shutting down server.

Error / logs

TypeError: Cannot read properties of null (reading 'map')
    at y (c:\Users\David.Jan\.positron\extensions\quarto.quarto-1.126.0-universal\out\lsp\lsp.js:367:21024)
    at async Object.computeOnSaveDiagnostics (c:\Users\David.Jan\.positron\extensions\quarto.quarto-1.126.0-universal\out\lsp\lsp.js:373:31192)
    at async Promise.all (index 0)
    ...

Node.js v22.17.0

Client Quarto LSP: connection to server is erroring. Shutting down server.
Connection to server got closed. Server will not be restarted.
Stopping server failed
Message: Pending response rejected since connection got disposed
Code: -32097

Environment

Extension: quarto.quarto-1.126.0-universal
Host: Windows (Positron paths: c:\Users...\ .positron\extensions...)
Node: v22.17.0
Happens: on open and/or on save (diagnostics)

Positron Version: 2025.10.1 (system setup) build 4
Code - OSS Version: 1.103.0
Commit: b13dd1ca4803bc04a4a9165395b589b8caf4ab58
Date: 2025-10-14T22:13:39.363Z
Electron: 37.2.3
Chromium: 138.0.7204.100
Node.js: 22.17.0
V8: 13.8.500258-electron.0
OS: Windows_NT x64 10.0.26200

What I’ve tried
Restarting the editor
Reload window

[mcanouil]

Important

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[mcanouil]

Could you provide the context in which this occurs? Some steps to reproduce?