At my workplace we use a custom language for which i made textMate grammar extension for VS Code.
This extension worked perfectly until the november 2025 update. The only change that i could find was a version bump for this textmate dependency.
Of course i might have missed another change, but it wasn't in the release notes at least.
my grammar definition was written in a file encoded using UTF-8+BOM. removing the BOM fixed the plugin, but this is a regression for all non maintained plugins that might be using this file encoding