Extension activation causes VSCode's Extension Host to crash

Describe the bug

Opening or creating any YAML file (empty or not) causes the VSCode extension host to crash.

Expected Behavior

The extension should work and not make the extension host crash.

Current Behavior

• Extension Host behaves as expected until a YAML file is opened (existing or after creation).
• Extension Host doesn't recover by itself until the VSCode window is reloaded.
• The content of the file doesn't matter (also occurs on empty files).
• This also occurs on a blank VSCode window, opening a single YAML file.
• VSCode's Developer Tools logs: developer-tools-logs.txt.
• VSCode's Output View doesn't list the extension, so no logs there.
• Installing different versions of the extension doesn't seem to change anything, I tried with those versions:
  • 1.24.2026052009 (pre-release)
  • 1.23
  • 1.15 (which I knew to be working on my machine prior)
  • 1.14 (which I knew to be working on my machine prior)

Steps to Reproduce

1. Open any YAML file with VSCode

Has been tested on a new VSCode profile, with blank {} User and Workspace settings, and only the single redhat.vscode-yaml extension installed.

Environment

• Windows 11 x64 10.0.26200
• VSCode 1.121.0
• Node.js 22.22.1

Reproduce the crash in a blank VSCode profile with only redhat.vscode-yaml installed, opening an empty or existing YAML file, and inspect the attached developer-tools-logs.txt. Compare behavior across the listed extension versions and the reported Windows, VSCode, and Node.js environment. Done means opening or creating YAML files no longer crashes the VSCode extension host.