TypeError: Cannot read properties of null (reading 'validProperties') when using LSP with Zed

[gursuj]

Hello. The Zed editor allows using this as an LSP (relevant docs). When using it with html files that have style tags/attributes, the error TypeError: Cannot read properties of null (reading 'validProperties') is thrown by the LSP. I've documented steps to recreate the issue (in Zed), a full log and workaround fix here. Other Neovim users have also faced this issue and used similar workarounds:

• https://neovim.discourse.group/t/help-with-diagnostics-for-html-files/2682/2
• html-lsp: "cannot read null 'validProperties'" when opening a html file with CSS <style> tag neovim/nvim-lspconfig#3393

[gursuj]

One of the Zed maintainers said they couldn't replicate this issue in VS Code so you'd have to use the LSP with something like Zed or Neovim to test this.