Ember's HTMLBars Compiler Error: Unexpected token export

I've inherited an Ember application at v1.8.1. I have successfully upgraded the application to v.1.9.1, and would like to continue to update it to at least v1.13.8.

In my v1.10.1 build, it appears that the ember-template-compiler is not quite meshing with Ember and am getting the following errors in the console:

Uncaught SyntaxError: Unexpected token export

Uncaught TypeError: Cannot read property 'name' of undefined

I'm looking for some direction in how to better track down the error, and what needs to be done to successfully upgrade.

The project is using broccoli (but not ember cli), so i'm trying to make the ember-cli-htmlbars plugin work.

Is there a better way to compile HTMLBars for Ember v1.10.1?

Should I transition the project over to Ember cli?

Please let me know what code you need would need to see.