CategoryTitleLinkComponent is undefined

I just upgraded my Discourse from 1.4 to the current tests-passed.

An error that I am having trouble with after the upgrade is:
Uncaught TypeError: Cannot read property 'reopen' of undefined in regards to Discourse.CategoryTitleLinkComponent.reopen (this is in one of my plugins).

So I am trying to search for why CategoryTitleLinkComponent is now undefined.

Some places I’m looking are the Category controllers and helpers/category-link.js.es6.

Have you read?

https://meta.discourse.org/t/deprecating-es6-compatibility-layer/35821

Thanks, @sam. I just read it. Something I am going to try:

• Removing changing Discourse.CategoryTitleLinkComponent.reopen to just CategoryTitleLinkComponent.reopen