Why can't I open the thing it nags me about an operator but how is that relevant I'm just trying to open the thing
Inline diagnostics was implemented earlier this year, and is still not enabled by default (likely to prevent breaking existing configs). The changelog is from January of this year:
https://helix-editor.com/news/release-25-01-highlights/
You can set it up here, and is straightforward:
https://docs.helix-editor.com/editor.html#editorinline-diagnostics-section