Sudden problems with Sage and BrowserSync

I have the same issue as described here.

Suddenly, out of the blue, when I use yarn start the main.css is not being found anymore, I just see the browser default rendering in localhost:3000 and example.test. I have to use yarn build instead, which causes another interesting error: mainly that the js router does not work anymore.

This worked fine every day for over two months now, and I have not updated anything. It just stopped working yesterday.

None of the things described here helped me with this issue.

The issue was that suddenly importing a js file (which I was importing before) was causing an error. It’s very interesting that yarn start breaks without notice on such a problem. Sorry if this was a duplicate of an already reported error.

how did you resolve the issue?

I fixed the JavaScript issue and the problem disappeared.

Another problem that sometimes appears is when there is an error in a javascript file, BrowserSync gets stuck on reloading all the time.