strange error when building...

[Luke-L]

when running npm run build in the extension folder i get the following console errors:

B:\Github\maxurl>npm run build

> [email protected] build
> npm run build-tsc && npm run build-js

> [email protected] build-tsc
> npx tsc

> [email protected] build-js
> node ./tools/remcomments.js userscript.user.js nowatch

about.js not found, not generating sites.txt
Updating...
Unable to find bigimage start/end -1 -1
Done

furthermore, when unpacking the chrome extension, it gives me these warnings:

• Unrecognized manifest key 'browser_specific_settings'.
• Manifest version 2 is deprecated, and support will be removed in 2023. See https://developer.chrome.com/blog/mv2-transition/ for more details.
• {"message":"The tab was closed."} undefined