Buttons and commands associated with a custom editor are gone under a certain scenario

<!-- ⚠️⚠️ Do Not Delete This! bug_report_template ⚠️⚠️ --> <!-- Please read our Rules of Conduct: https://opensource.microsoft.com/codeofconduct/ --> <!-- Please search existing issues to avoid creating duplicates. --> <!-- Also please test using the latest insiders build to make sure your issue has not already been fixed: https://code.visualstudio.com/insiders/ --> <!-- Use Help > Report Issue to prefill these. --> - VSCode Version: 1.49.1 - OS Version: Ubuntu 20.04.1 LTS Buttons and commands associated with a custom editor are gone if you define a language in the `package.json` and a different file association in the `settings.json`. You can reproduce this issue by doing the following changes on the [custom-editor-sample](https://github.com/microsoft/vscode-extension-samples/tree/master/custom-editor-sample): 1. Add these contribution points in the `package.json` ```json "menus": { "commandPalette": [ { "when": "resourceLangId == pawDraw", "command": "catCustoms.pawDraw.new" } ], "editor/title": [ { "when": "resourceLangId == pawDraw", "command": "catCustoms.pawDraw.new", "group": "navigation" } ] }, "languages": [ { "id": "pawDraw", "extensions": [ ".pawDraw" ], "aliases": [ "pawDraw" ] } ] ``` 2. Add this config in your `settings.json` ```json "files.associations": { "*.pawDraw": "xml" } ``` Since the custom editor works fine even with this file association, I'd expect commands/buttons associated with this custom editor working fine as well. Please let me know if this behavior is expected or if this is indeed a bug. See:  /cc @mjbvz