Console errors MIME + SketchUp API

“Refused to apply style from ‘url’ because its MIME type (‘text/html’) is not a supported stylesheet MIME type, and strict MIME checking is enabled.”

this msg i have on server side, I researched the net but everybody says something else….If somebody had this and solved it, please tell me.
I have integrated a player von sketchup in my annotation, which works good local. But on my server side I get this:

“DevTools failed to load SourceMap: Could not load content for https://static.sketchfab.com/static/builds/web/dist/npm.getstream-cd062b73407a206b1c84a9faa0605f01.js.map: HTTP error: status code 403, net::ERR_HTTP_RESPONSE_CODE_FAILURE”. and this: “you are using a deprecated api, please update to the new one, read mode xxxx”