Ember application runtime error uncaught referenceerror ember is not defined vendor.js

Question

I'm trying to upgrade the ember from 3.* to 4.12.2. I'm not getting any compilation issues but when I run my application I'm getting "uncaught referenceerror ember is not defined" inside the vendor.js file.

below is the console log in browser.

vendor.js?v=95293905-3319-4db8-8355-c1297659dfa6:98  Uncaught ReferenceError: Ember is not defined
    at a.callback (vendor.js?v=95293905-3319-4db8-8355-c1297659dfa6:98:389464)
    at a.exports (vendor.js?v=95293905-3319-4db8-8355-c1297659dfa6:1:2153)
    at a._reify (vendor.js?v=95293905-3319-4db8-8355-c1297659dfa6:1:2747)
    at a.reify (vendor.js?v=95293905-3319-4db8-8355-c1297659dfa6:1:2532)
    at a.exports (vendor.js?v=95293905-3319-4db8-8355-c1297659dfa6:1:2125)
    at a._reify (vendor.js?v=95293905-3319-4db8-8355-c1297659dfa6:1:2747)
    at a.reify (vendor.js?v=95293905-3319-4db8-8355-c1297659dfa6:1:2532)
    at a.exports (vendor.js?v=95293905-3319-4db8-8355-c1297659dfa6:1:2125)
    at a._reify (vendor.js?v=95293905-3319-4db8-8355-c1297659dfa6:1:2747)
    at a.reify (vendor.js?v=95293905-3319-4db8-8355-c1297659dfa6:1:2532)

Any help appreciated, Thank you in advance.

Regards

I tried removing deprecated libraries, tried using auto import still getting this same issue

Answer 1

In Ember v4 using Ember without importing it was removed. This was deprecated in v3.

Your screenshot of the problem area was most helpful -- it reveals that ember-islands/utils/reconciler needs to have import Ember from ember` in it. It seems like the latest version has that import, so hunch is now that something is going wrong with the polyfill included here: https://github.com/mitchlloyd/ember-islands/blob/master/package.json#L23-L24

To unblock your upgrade, I would use patch-package or npm/yarn/pnpm overrides to update the dependencies of the library -- it looks like it's had no maintenance in the last 4-5 years, so if you want to continue using it -- you may need to fork (this has the advantage, where you can also make the addon do whatever you want).