Bug 446939

Created attachment 144517 [details]
Screenshot of Output pane

SUMMARY
I was attempting to use the HTML LSP provided by Microsoft Visual Studio Code
https://github.com/microsoft/vscode/blob/main/extensions/html-language-features/server
provided by
https://github.com/hrsh7th/vscode-langservers-extracted

It seems to run fine, but on run prints an error to the LSP console


STEPS TO REPRODUCE
1. Install https://github.com/hrsh7th/vscode-langservers-extracted with npm install -g vscode-langservers-extracted
2. Add the following to your LSP servers

        "html": {
            "command": ["vscode-html-language-server.cmd", "--stdio"],
            "url": "https://github.com/hrsh7th/vscode-langservers-extracted",
            "highlightingModeRegex": "^HTML.*$"
        }

3. Open an html file.

OBSERVED RESULT
Plugin seems to run okay, but the following is printed to the console

17:45:59 LSP Server Error html@C:/Users/Jonathan R
   Unhandled exception: client/registerCapability
   Error: client/registerCapability
       at handleResponse (C:\Users\Jonathan R\AppData\Roaming\npm\pnpm-global\5\node_modules\.pnpm\vscode-jsonrpc@8.0.0-next.4\node_modules\vscode-jsonrpc\lib\common\connection.js:510:48)
       at processMessageQueue (C:\Users\Jonathan R\AppData\Roaming\npm\pnpm-global\5\node_modules\.pnpm\vscode-jsonrpc@8.0.0-next.4\node_modules\vscode-jsonrpc\lib\common\connection.js:308:17)
       at Immediate.<anonymous> (C:\Users\Jonathan R\AppData\Roaming\npm\pnpm-global\5\node_modules\.pnpm\vscode-jsonrpc@8.0.0-next.4\node_modules\vscode-jsonrpc\lib\common\connection.js:292:13)
       at processImmediate (node:internal/timers:464:21)


EXPECTED RESULT
Plugin runs without errors


SOFTWARE/OS VERSIONS
Windows: 10 Home 21H1 19043.1348
macOS:  N/A
Linux/KDE Plasma: N/A
(available in About System)
KDE Plasma Version: N/A
KDE Frameworks Version: N/A
Qt Version: N/A

ADDITIONAL INFORMATION
The following info message is also printed when the plugin starts

17:45:59 LSP Server Info html@C:/Users/Jonathan R
   Registering request handler for workspace/didChangeWorkspaceFolders failed.