Request textDocument/hover failed

Sometimes I open other file types (html, css) and I got these error:

hover to a color value in a css file:

opening a css file:

I think it's not necessary to display these warnings.

Thanks!

Reproduce the reported textDocument/hover failures with HTML and CSS files, including hovering a CSS color value and opening a CSS file. Start at the extension's hover handling or language-server request path; done means these cases no longer show unnecessary warning messages without affecting ActionScript or MXML behavior.

Written by the indexing model from the issue text.