I'm trying to convert an extension to Manifest V3 and begun by making the necessary changes to the manifest.json file and creating a service worker entrypoint script which simply imports all the scripts that used to be listed in the background section under MV2. When I try to load the extension it loads fine but there's an error logged under the Errors section "Service worker registration failed" with
highlighted in the error. It seems like chrome sees the file, because if I change the manifest entry to a file that does not exist and try to reload the extension I get a popup error instead saying
Could not load background script 'not-a-script.js'.
I've seen the post about the service worker having to be at the root directory and so it is placed there. I cannot think of what else to do and the error message does not give any more precise information on what's wrong.
Running Ubuntu 18.04 and Chrome 88.0.4324.150