An unknown error occurred when fetching the script (Service Worker)

Question

When going offline, I get the following error by my service worker:

(unknown) #3016 An unknown error occurred when fetching the script

my service w

Answer 1

Before trying anything else, check whether your https certificate is invalid or not matching the url you are accessing.

E.g. In my case I was trying to access https://localhost with a certificate that was registered for another domain.

While hitting "proceed" would allow me to enter to the site, this exact error would be printed to the console:

An unknown error occurred when fetching the script