CRA - 无法注册 ServiceWorker，不支持的 MIME 类型 ('text/html')

Question

I am getting the following error when publishing my create react app but the error doesn't appear locally. I recently updated my React version and a load of packages too. I'm guessing it's possibly something to do with that as I've never had this issue before?

Error during service worker registration: DOMException: Failed to register a ServiceWorker for scope ('https://**subdomain**.azurewebsites.net/') with script ('https://**subdomain**.azurewebsites.net/service-worker.js'): The script has an unsupported MIME type ('text/html').

Any input on this will be greatly appreciated. The error doesn't appear to be breaking anything from what I can see but I'd rather not push this to production with any kind of errors

Answer 1

So turns out the issue was because I updated the react version. CRA doesn't have service workers out of the box anymore. The project was returning 'unsupported MIME type ('text/html')' because it was hitting 404 looking for a file that doesn't exist. The fix was relativly simple. I replaced the registerServiceWorker() in my index.js file with reportWebVitals() . I then added reportWebVitals.js to my src folder. (I just created a temp react project and pulled the file from that). After I did that it started to work for me. I think I also had to npm install web-vitals.